This is an FAQ that I stole from the backcountryclub.org website, but I helped create the damned thing so I have the right to.
What is the backcountry?
Any place outside of ski resort boundaries is considered backcountry. If it is unmaintained (this includes avalanche control, grooming, hazard markings, and ski patrol) it is backcountry, regardless of the proximity to a resort or an urban area.
Is backcountry skiing/snowboarding dangerous?
It can be. In the backcountry, you and you alone are responsible for your own safety. With the freedom to explore your limits comes the responsibility of making the decisions that determine the level of risk that you are exposed to. Proper education and good wilderness habits greatly limit the amount of unintended risk. The amount of danger you are exposed to is completely your decision, it can be as mundane as a quiet tour in the woods, or as intense as a ‘you fall, you die’ slope. The choice is yours.
Do I need any special training to go into the backcountry?
While prior training or experience isn't a necessary requirement to get into the backcountry on your own, it is highly recommended to acquire the basic knowledge for safe backcountry travel. These include navigation and route finding skills, and avalanche training. Often, backcountry enthusiasts receive avalanche training, read literature that outlines the basic skills, and go out with others who have been backcountry skiing before. Recommended books include: ‘Mountaineering: Freedom of the Hills’, ‘Staying Alive in Avalanche terrain’, and ‘Allen and Mike’s Really Cool Backcountry Ski Book’.
Do I need any special equipment?
Yes. It is highly recommended that you carry avalanche rescue equipment (beacon, probe, and shovel). You should not go into the backcountry without all three. It is also necessary to have a means of climbing up (skins, an alpine touring or a telemark setup, a splitboard or snow shoes).
Why can’t I just hike up in my boots?
Wading through waist-deep snow is extraordinarily tiring. If you were to reach the summit, you would probably be too tired to enjoy the ride down. Do yourself a huge favor; use the correct gear.
What are skins?
Skins are generally adhesive-backed nylon strips. They have glue on one side and a fur-like surface on the other. They attach onto your skis or splitboard to provide the grip needed to ascend the slopes, and peel off for the descent.
What is AT?
AT stands for alpine touring. An AT binding is a ski binding that unlocks at the heel for traversing and climbing and locks down for descending. There are a number of brands and models, many that are compatible with standard alpine ski boots. There are also alpine touring boots. These have rubber soles and usually a walk mode, some have inserts that allow for the use of special AT bindings. They are often lighter than alpine ski boots and better for hiking.
What is a splitboard?
A splitboard is a snowboard that splits (hence the name) into a pair of skis for traversing and climbing, and can be converted back into a snowboard for the descent.
This all sounds like a lot of work?
It is. There is a reason that ski lifts were invented. All skiers used to be backcountry skiers, now backcountry is the minority. If you like getting off the beaten path and away from the crowds, all that is normally required is a little work.
Do I need to be an expert skier or snowboarder to go into the backcountry?
No. It never hurts though. The snow found in the backcountry is highly variable, much more so than found at the resorts. This can lead to difficult conditions. The more proficient you are, the more often you will stay upright, but at least the snow is typically soft when you fall.
What things should I bring on a tour into the backcountry?
The exact list of items will depend on the extent of the tour, but there are some that should be brought every time.
First the gear needed for your chosen descent method (AT, telemark, or snowboard) see prior question.
Beacon, probe and shovel. The trinity of avalanche rescue gear.
Water, at least a liter maybe two depending on the trip
Food, trail food is best, energy bars, trail mix, sandwiches, etc.
Sunscreen
Extra clothing; it is best to dress in layers. You will be much warmer on the way up than on the way down.
Sunglasses and goggles; you will often want both.
Map, compass, and/or GPS. Especially if you are unfamiliar with the area.
Duct tape, zip ties and a multi-tool. Things break.
Why do I need a beacon, probe and shovel?
Because people make mistakes. While having avalanche rescue gear does not guaranty you will survive being buried in an avalanche, not having them guaranties that you will not.
Where can I find places to tour?
If you live in Colorado, the trip reports in the forums section of the backcountryclub.org website is a great place to find information on snow conditions and terrain. There are also several backcountry skiing books on the market. Once you get into things though, you might find yourself just looking at TOPO maps or perusing Google Earth to find your next potential ski descent.