BACKPACKING GEAR:  We were very excited, and also a little nervous, when we embarked on our first four-day backpacking trip on the Ice Age Trail in Wisconsin.  We were preparing to travel to Peru to summit the nearly 19,000 foot Mount Pisco, as well as do the 5 day Salkantay Trek.  We wanted to make sure we were in shape, as well as try out our gear before we went on that trip.  So far, our longest backpacking trip has been 6 days, and we average between 15 and 20 miles per day.  In addition to the Ice Age Trail and Peru, we have done trips in Yosemite, Zion, Bryce, Yellowstone, and Rim-to-River Grand Canyon (both sides).  We haven't graduated to be bad-ass distance hikers yet!  Eventually we want to do some longer trips, and maybe even tackle a long thru-hike.  

Much of the basics for hiking apply to backpacking, but obviously you need some different gear for multi-day trips.  There is also less room for error when you are going to be gone for a longer period of time!  We needed all the gear when we started, and we knew nothing about it.  We gained invaluable knowledge from attending seminars, reading articles on-line, and talking to lots of people.  We had a bit of sticker shock when we started to look for our equipment.  It can cost a lot to go out in the woods!  One piece of advice an experienced hiker gave us was to focus our spending on the three "B's" that are most important to comfort:  Boots, Bag (sleeping bag, that is!), and Backpack.  In the world of expensive gear, this helps narrow down what is important.  We got most of our backpacking gear from REI and Moosejaw, filling in with some items from local outfitters along the way.   Here is what we use, as an example, if you are just getting started.    

PACK - Packs are sized by the amount of liters they can hold.  For backpacking, you will probably need around 65 liters minimum.  We both love our Deuterpacks - although there are other great brands such as Gregory and Osprey.  Barbara's pack size is a 60+10 and Oscar's is 65+10.  We definitely have maxed them out on our trips, especially when we carried a lot of cold weather gear for our Peru trip, and when we had to carry food in bear canisters.  In addition to liter capacity, they are also sized to fit various torso lengths.  Make sure that you choose a pack sized to fit you to avoid shoulder or back pain.  Consulting with someone at an outdoor retailer can be very helpful here, as they know how the pack should fit you when it is weighted down. Two other features we think are important are:  1) Water reservoir system (we find we drink much more if we use a water reservoir pouch with a tube that runs out of our packs, and we always carry minimum 3 liters with us) and 2) Rain covers.  Many packs have both these features included.  If not, we recommend you buy them to work with your pack.  Another "trick" we have learned with our packs is to use heavy duty trash compactor bags inside them to act as a cheap and durable waterproof liner.  We haven't had our backpack contents wet yet!  Another suggestion is to attach carabiners and / or key rings on your pack to attach whatever needs to be attached.  Handkerchiefs, mugs, whistles, etc!   

TENT - A three season tent should be adequate for most backpackers.  Tents can get pretty expensive, and mostly it is based on weight.  Another consideration for tents is whether they are free-standing, a consideration if you think you might be pitching it on solid rock or other places where you can't put in any stakes.  We haven't run into this yet.  When we were looking for tents, we went into REI, and they let us set up a bunch of them right there, so we could see how the set-up was, and how roomy they felt.  For us, we wanted doors on both sides, and a little bit of room inside.  While we considered a bunch of options, we ended up settling for a relatively inexpensive tent - the Eureka Spitfire 2.  When we decided to buy a second tent recently to have when we have family members join us, we went through the process again, and after trying out a bunch of tents again, we bought another Eureka.  We just couldn't justify the significantly higher cost for other tents, and the Eureka has more room.  It is slightly heavier than some other options, but since we share our load, it was not significant enough to matter.  

You can also make a footprint liner out of nylon fabric to put under your tent to help protect it and keep it dry.  We did this, but don't carry it with us all the time.  You can also buy them, but when I say "make" one, we just bought two pieces of nylon and lay them down.  

SLEEPING BAG -   You should buy a down sleeping bag, not synthetic.  They will generally give a temperature range on them - buy one rated about 15 degrees colder than the temperature you would want to camp in.  A good start is one rated for around 10 to 20 degrees, or 850 fill.  We chose our sleeping bags in anticipation of our trip to Peru, so we bought bags for pretty cold weather. We have used them for all our trips, although they have been a bit warm for some of the places we've been.  The way we have dealt with this is to take a bag liner with us as well, and sleep on the heavy bag and inside the bag liner, and just cover up with the bag as needed.  Eventually, we may have to break down and get a lighter bag, but they are pretty expensive so we are trying to make do for now, and since we like to backpack in mountains, it tends to be on the cooler side.  We both have WesternMountaineering Gore Windstopper bags - Oscar kas the Kodiak 0 degrees, and Barbara has the Lynx -10 degrees.  We have only used this one bag, so we can't say from experience, but we have been told that WesternMountaineering and other high-end bags such as Feathered Friends, Berghaus, and Valandre are significantly better than mid-range bags like Rab, Sierra, and Mont Belle.  This is an item that it might be worth the splurge so that you don't end up buying a bag that you're miserable in, only to turn around and buy another one.  A little side note - our bags came with a choice of what side the zipper is on.  We didn't think about it at the time, but it may be worth it to pay attention to your sleeping habits and pick the side that the zipper feels more natural on, for instance if you tend to sleep on one side.  Or if you hike as a couple, you might want to have zippers facing each other.  

I mentioned bag liners - I always carry a silk liner with me for more warmth, (or a light option if it is warm) and to keep my bag clean.  There are also heavier liners you can get to make your bag warmer.  You also should get a waterproof compression bag (we useSea-to-Summit large size) to put your bag in while hiking, but don't store it in there!  Keep your bag fluffed out as much as possible and preferably hanging up when you aren't using it.   You also should get a sleeping pad to keep you more comfortable and warmer.  We like the Thermarest self-inflating pads.  

COOKING SYSTEM -  We use the JetBoil system, and it has worked fairly well for us, mostly eating dehydrated meals.  We started out with a Zip and a Flash.  The Zip has a smaller cup with it and I get frustrated because I can't even make ramen noodles (half a pack) in it.  It boils over too easily.  The Flash size works okay, and I like the igniter on it, especially when it's cold and my hands aren't working well to use a lighter.  The only thing I don't like about the Flash is that it is tall, and hard to eat out of.  Since we always travel as a pair, we currently carry both the Zip and the Flash, and most meals I use both of them to have enough water for hydrating meals and drinks.  When I replace these, I will most likely get the MiniMo, since it is larger and has a pot-like shape instead of the taller cup.  

We went through several sporks, and after breaking a few, and not being able to reach into our cups with a few, we finally found a long Sea-to-Summit spork that works well.  We also each carry a mug with us so we can have coffee in those if we have food in our JetBoils.  

WATER FILTRATION AND STORAGE -  We carry our 3 liter water reservoir full in our packs, as well as 2 one-liter nalgene bottles with us.  A hint on water reservoirs - when you are not using them, keep them in the freezer to keep them fresh!   For water treatment, you can use a pump filter or chemicals.  We opted for a pump since it makes the water more palatable, and also we can drink the water immediately.   We are very happy with our Katadyn, and their site helps you choose the right filter.  

FOOTWEAR - This is extremely dependent on the terrain you are hiking in, how much weight you are carrying, and your personal preference.  I've read a lot of articles about thru-hikers carrying heavy packs who hike only in trail runners or other trail shoes.  We would not be comfortable with this because of the strain on the arches and ankles.  On the other extreme, a lot of people we have run into wear heavier, stiffer boots with higher ankles that they feel is important for stability.  An example would be the Lowa Tibet.  For us, we have been happy wearing our Lowa Renegade GTX boots - the same boots we wear for most of our day hikes.  We haven't noticed any foot fatigue or other problems, even with packs up to 50 pounds, and 15+ hiking miles average per day (up to 22 miles) on fairly tough terrain.  I will say that they wore out a little more quickly than we expected (some people say they replace their Renegades about every year - ours lasted over two years), but they are the right mix of support and lightness for us with our current pack weight and mileage.  Be sure to buy boots about a size larger than you normally wear to allow for swelling.  We didn't do this at first, and ended up selling our first set of boots within a month or so of buying them.

Other items to consider for your feet are insoles, socks, and gaiters.  We always buy a better insole to put into our boots to provide better arch support than the manufacturer supplied insoles.  Barbara prefers the very sturdy Superfeet brand, while Oscar prefers the more cushioned SofSole.  This is a significant additional investment after you buy shoes, but the health of your feet are critical if you want to enjoy hiking.  For socks, we strongly recommend merino wool because they stay comfortable, don't get smelly like other materials, don't tend to cause blisters, and keep you warm even if wet.  Smartwooland Fits are our two favorite brands. You can also try liners if you have any problems with blistering.  The last item, gaiters, are protective covers that cover your lower leg and top of your boot, and are very helpful if you are hiking in some snow, doing river crossings, or hiking in rough, bushy terrain.  They help keep your feet dry, and your pants cleaner and less torn up.  We use the Outdoor Research gaiters.   

APPAREL -   Packing for our trip to Peru, we learned the layering system - up to 5 layers on top, and three on the bottom.  As a rule, we do not wear any apparel made of cotton (even underwear and bras!), because cotton tends to chafe and if you get sweaty and then get cold, cotton will make you colder.  We stick to merino wool or quick drying performance clothing depending on our activity and the temperatures.  We also like down for its light weight and compact size.  You can obviously mix and match as needed.  Even in Peru, we did not need all the layers on together, since our bodies heat up quickly when hiking.  But it is good to have them all to adjust.

   - Top:  5 layers.  Base - wool or fast drying synthetic.  Second layer fleece or down, third layer soft shell jacket, fourth layer Puffy down jacket 600 to 850 fill, fifth layer       Hard shell (waterproof) jacket.  It is important not to let your body overheat and get sweaty, because once you stop you will get cold fast!  

   - Bottom:  3 layers.  Base - wool or fast drying synthetic, Second layer nylon pants or soft shell pants if it is cold.  Third layer hard shell (waterproof) pants.  We have         never ended up using our waterproof pants yet.  They are pretty stiff and cumbersome - I would have to be pretty cold or really drenched to want to wear them.  

   - Other:  Gloves - if you need gloves, you probably want to go with windstopper.  I wore two pairs of gloves part of the time when we were in Peru.  A wool hat and a       neck buff or balaclava are also good considerations if you are going to be hiking anywhere cold.    

TREKKING POLES - While not required, we have found that we strongly prefer hiking with our poles to ease the load on our knees, and aid in balance, especially in "sketchy" situations like creek crossings, or steep slopes where it helps to have added balance.  Choose an option with a foam or cork handle, and flick locks (not screw locks).  We have had great luck with our Black Diamond poles.  

TROWEL - Don't forget you will need to bury your solid human waste properly.  You should carry a small light-weight trowel for this little chore.  We also learned to use small, empty, coffee bean bags (the metallic kind that roll from the top) to put our used paper in to carry out with us.  They hold in the smell!  Be sure to follow Leave No Trace principles .  

SURVIVAL GEAR - Even though we always hike together, we both carry each of the things below, with the exception of the InReach.  This is in case we ever get separated, or lose one of our packs down a river or something.  

     - Compass and a printed map of the area where we are hiking.  You need a topo map with adequate level of detail to navigate.  We like the Nat Geo maps, but                   there are many more out there.  We highly recommend taking a navigation or orienteering class so you know how to use your compass and map!  We also carry           our InReach as an emergency navigation and signalling device, but we never rely on it for navigation.  We bought it mainly for the satellite emergency                               beacon system when we started canyoneering and doing some hikes in pretty remote places.  

     - Knife - we prefer a multi-tool type knife such as a Swiss Army Knife or Leatherman, but even a basic pocket knife is invaluable.

     - Headlamp - We carrier a better headlamp for our backpacking trips since we know we will be using them.  Our current favorite is the Black Diamond Storm.

     - Whistle to signal for help if needed - make sure it is somewhere accessible and not at the bottom of your pack!

     - Multi-day first aid kit.  Adequate quantities of bandages, antibiotic cream, benadryl, pain relievers, and blister care.  You can buy them pre-packed, or make your             own in a waterproof pouch.  If you make your own, you can "cheat" and look at contents of a pre-made kit!  Taking a basic wilderness first aid course is also a                 great idea.

     - Fire-starting tools - we carry a lighter as well as a small emergency magnesium fire starter and a small tin or pill bottle with cottonballs soaked in vaseline.

     - Duct Tape - we carry some wrapped around our lighters, pencils, and nalgenes.  You can wrap a little around anything so you always have some.

     -  Paracord is light and can be invaluable for securing whatever needs to be tied down.  It can also be used for splints or as part of creating a shelter. 

     -  Survival kit - we carry a pre-made SOL survival kit that carries some of the things that we carry separately as well, and some additional items such as fishing kit,             emergency blanket, etc.  Obviously, you can compile your own survival kit as well.  We liked this one because it was compact.