A good backpacking stove can be a comfort and even a lifesaver in the woods, giving you the ability to prepare hot food and beverages in cold and remote locations. The knowledge of how to use your stove (or those of your friends) efficiently and safely is just as important, and requires study and practice.
Backpacking stoves are lightweight cooking devices that take up little room in your pack and can be assembled quickly and easily in the field. There are basically three main types: Disposable canister stoves, old-school self-contained white gas stoves, and detachable-bottle white gas/multi-fuel stoves.
Disposable canister stoves normally burn a combination of iso-butane and propane gas, and include brands such as Gaz, Bleuet, Primus, MSR, Snow Peak and Coleman. Since the gas canister usually supports the unit there is less to build and these stoves tend to be fairly inexpensive. In addition, they are relatively safe for young users since there is no pouring of liquid fuel involved (when you are finished with a cartridge, you simply throw it away and install another). Modern canister stoves like the MSR Pocket Rocket are also among the lightest stoves available for backpacking. Disadvantages include the high cost of fuel canisters, relative instability when cooking large amounts of food, the inability to top off a canister or gauge it's fullness once it has been punctured, and poor performance in cold weather. Also, you may have difficulty locating the specific fuel canister you need when you need it most (although some, such as the MSR Super Fly, will fit almost any brand of fuel canister). Many of these stoves are available with lightweight piezo starting devices which make lighting the stove simple and safe (and are a lifesaver if you forget matches).
The "old school" self-contained white gas stoves are units where the fuel tank and the burner/jet assembly are attached more or less permanently. These include the venerable Svea 123R and Optimus 8R and many of the Coleman Peak I series, some of which also burn multiple fuels. Advantages include simplicity of operation (they tend to have few moving parts and you can usually get the thing to work in the field by spending a little time cleaning the jet), cheap operation (a gallon of camp fuel costs less than $6 and lasts for a couple of years even if you use it a lot) and worldwide availability of fuel. These stoves can often be bought at garage sales for a few dollars, as well. They are relatively messy, however, and require the pouring of white gas from bottle or can into the fuel tank of the unit, which must be done under adult supervision during Scout outings (you can save time by making sure the stove is full before you leave home). If you get one of these stoves, make sure it has a pump on the fuel tank to build up pressure for priming or cold weather operation (or buy an auxiliary pump).
The versatile detachable-bottle class is the third group, as represented by companies like Primus, Coleman, Snow Peak and the ubiquitous Seattle-based MSR. Many backpackers favor these stoves for their relative economy, superior cold weather performance and the fact that the fuel storage tank doubles as the operating tank, thereby saving weight. They are refillable and many can use a variety of fuels, including kerosene, aviation fuel, unleaded gas and white gas (most require changing the jet to use fuels other than white gas). The Coleman Peak I Apex, Primus Himalaya, Snow Peak GigaPower, and MSR Whisperlite, XGK and Dragonfly are all reliable performers, with prices running from around $50 to $150.
For most scouting overnights and multi-day camping, any of these units will serve the purpose. A trip to REI downtown is a good idea just for the sake of comparison shopping; many of these stoves will be set up and you can try them out; the personnel make a point of being patient with first-time users. Also, try using an extended-nose lighter instead of matches (the ones you get to light pilot lights or barbecues). You get hundreds of lights out of a single lighter, have no matches to dispose of, and you keep your hands out of the flame in case the stove flares up upon lighting. Never remove the filler cap of a stove or try to fill it while the stove is burning or hot, since the gas is pressurized inside the tank.
The most important thing to do once you have found a stove is to thoroughly familiarize yourself with its operation. Take the time to learn to fill the stove, prime it if necessary, and light it, then shut it down. Practice making a cup of hot chocolate or a bowl of Top Ramen in your yard before you take it camping to ensure that you’ll be able to use it when it’s dark or cold and windy in the field, and read the trouble-shooting instructions that come with the unit that tell how to clean and care for your stove. With proper care, most of these stoves will last for decades and help warm you up for years in the mountains.