What to Pack 101
What exactly should you carry in your backpack? The answer to this varies widely based on your experience level, your desired comfort level, the miles you plan to hike, the anticipated conditions and weather, and your budget. A good place to start is the "Ten Essentials." This list is widely considered the basic list for outdoor survival. If you want to see what I chose to bring when I set out on the Appalachian Trail, check out my Appalachian Trail gear list, link below. Note that nearly everything stayed the same until I got off the trail, except my backpack!
The New Ten Essentials
Traditionally this meant a map and compass. In modern times, there are more options. Except in special circumstances (such as on the Appalachian Trail when attempting a thru-hike) I would still say that a Map, at least is a necessary piece of equipment, since electronic alternatives can fail for a variety of reasons, battery loss, cold weather, and exposure to moisture, or dropping on a rock being to name a few. I like to use Tom Harrison Maps, when available, as well as the Guthook hiking applications on my phone.
When I was on the Appalachian Trail I used AWOL's physical guidebook as well as the Guthook Appalachian Trail Guide app on my phone. In the Sierras, or more remote locations having a map, as well as a compass which shows a variety of exit routes from the wilderness can be the difference between getting help, and getting stuck. Even experienced hikers can get lost of disoriented, and lacking navigational tools will set you up for failure.
2) Sun Protection
The level of sun protection you'll need will vary depending on the nature of your trip. If you are backpacking the the Great Smoky Mountains in March, it will be very different to backpacking in the Mojave Desert in March. Be aware of the level of sun protection you are likely to need. If you will be backpacking over snow, sunglasses, and sunscreen are a must, as the brightness of the sun's reflection off the snow can lead to severe sunburns in unusual places, such as under your chin, and can also cause "snow blindness". Use your best judgement. Sunscreen is also important if you are going to be at higher altitudes, because there is less atmosphere to protect you from UV radiation, which means it is easier to get sunburned. For some trips I like to bring a trekking umbrella for sun as well as rain. zPacks and Six Moon Designs both sell a branded version, but this one on Amazon is essentially the same, and the one that I own. A trekking umbrella certainly isn't necessary, but sun protection is.
You should be prepared for the coldest possible weather for the season and location you are backpacking in. Watch the weather forecast but know that you can lose 10 degrees for every thousand feet in elevation you climb, and most weather stations are at lower elevations. This is not an area where I try to save weight by under preparing. I save weight by purchasing warmer options that weigh less. For example I use a backpacking quilt instead of a sleeping bag. I find them to be more comfortable, and they are significantly lighter for the same weight. You should also have a jacket, a beanie, and possibly long underwear. If this is your first backpacking trip err on the side of caution.
Rule number one? NO COTTON! Most backpackers prefer either wool, or synthetic fabrics, but that is a matter of personal preference. Wearing cotton is not a matter of personal preference. There is a saying in the woods: "cotton kills." Take that seriously. Insulation should also include some kind of rain protection, depending on the conditions.
You will also need a sleeping pad. This insulates you when you are sleeping, because the ground can be a source of heat loss without it. To determine the insulation qualities of your sleeping pad, check the "R-value," the higher the R-value, the more insulative the sleeping pad is. If you are on a budget, a blue foam pad from Walmart or your neighborhood outfitter is generally sufficient during the summer months, though I prefer the inflatable pads that Thermarest makes for comfort. Please don't use a yoga mat. They are exceptionally heavy and are not good insulators.
You'll need something to see and be seen. You may not plan to night hike, but delays can happen. Illumination will also make it easier to find you if you get lost! I, like most backpackers, prefer a headlamp for hands-free illumination.
Consider this, if you ever want to get somewhere by sunrise, you're going to have to night hike
5) First Aid Supplies
Anything that can happen, will happen. You might fall, you might get stung by a bee, you might get burned by your stove. Consider your risk tolerance level, the number of people in your group, and their age and experience level to help you figure out what first aid supplies you'll need. I always pack bennadryl, IB profin, band aids, Imodium and Pepto Bismol. If I'm hiking with people that are younger teens, or have less backpacking experience than me, or if we are going to be on an especially risky trail, I bring more.
You should bring at least two methods to start a fire. That's the advice my dad always gave me growing up. I will normally carry two bic mini lighters, and, if I'm going to be facing cold conditions, matches. Since lighters aren't as reliable when it's cold. Either way, you should have some way to start a fire, in case of emergency. Make sure that you are following the fire regulations where you are traveling if you start a camp fire. these are not allowed in many places at high elevations, or where there is high risk of wildfire.
7) Repair Kit and Tools
Thing break. Figure out what will be critical if it breaks. Like your tent pole, or your sleeping pad. Often Duct Tape wrapped around your trekking poles will be enough to get you back into town or to a road crossing.
You need some calories to move you forward.
Lucky you, I already have a whole post on this topic!
Hydration is key in the backcountry. Everyone has their own preferences for filters, water bottles, and sourcing. I prefer to camp near a water source. I use a Sawyer Squeeze and smart water bottles. There are plenty of options, but if you are a beginner, bring more than you think you need, with water, it is much better to have too much than too little.
If you are new to backpacking, your best bet will probably be to borrow whatever your backpacker friends and relatives have in the garage until you are ready to make an investment. If you're a tarp-pitching pro, or the kind of the free-standing tents, you still need a place to stay, in case the weather gets dicey.
Mags is an expert backpacker who's blog I've enjoyed for a long time. He is experienced, and sensible, and frugal. For more information about what to pack, check out his beginers guide.