Tricked out boards and tech bindings get all the attention, but in reality your snowboard boots are the most important part of your setup. Boots that are too stiff, too soft, not warm enough, or just plain don't fit right will not only make you miserable, they'll actually prevent you from riding at your best.
Buying Your First Pair of Snowboard Boots
The best place to buy snowboard boots is at a reputable snowboard shop. The sales staff at these shops are snowboarders, so they'll know right away what does and doesn't work for snowboarders. Ask around - friends, instructors and locals are your best resources when looking for a reputable shop. Especially when buying your first pair of boots, resist the urge to save a few bucks by shopping online. Saving a few bucks just isn't worth it compared to the frustration and pain that can come from riding in the wrong boot.
Shop Till You Drop
Be sure to try on several pairs of boots to get a good idea as to how the different brands and models fit. Some brands fit wider feet better, some fit riders with narrow ankles better, etc. Make sure to bring the socks you ride with along as well, in order to get an accurate fit. TALK to the sales staff - let them know where you ride, how long you've been riding, and the type of riding you do. They know their stuff, but they still need as much information as possible to get you into the right boot.
Read More on How to Fit Snowboard Boots
The Proper Fit
Every move your board makes starts with input from your feet. Because of this, snowboard boots should fit snugly, with the tips of your toes just barely brushing the front of the boot. Heel-lift should be minimal to non-existent. Boot liners will "pack-out," or compress over time (usually several days to a week of riding), usually yielding an additional half-size. Keep this in mind and aim for a comfortable boot that is a half-size smaller than your street shoe.
Snowboard boot lacing systems can be divided into traditional and the newer high-tech "speed-lace" systems being offered by several manufacturers. Traditional laces are just that - long shoelaces that can be purchased nearly anywhere for a few bucks. Advantages include wide availability and the ability to replace them on your own. Disadvantages are mainly the amount of time it takes to lace the boot. Speed-lacing systems consist either a single or two main laces that require a simple tug to lace the entire boot. Advantages include ease of use and speed; disadvantages include the inability to replace them yourself.
Soft vs. Stiff Boots
More advanced riders as well as larger riders will generally need a stiffer boot than small or beginning snowboarders. Stiffer boots respond faster to your movements, provide more support for heavier riders, and are well-suited to faster, more aggressive riding styles. A good way to tell if a boot is too stiff is to raise your foot off the ground and try to flex your ankle as if you were pressing the gas pedal on your car. A boot that's too stiff will prohibit the necessary ankle flex, which in turn hurts your riding.
Snowboard Boot Pricing
Snowboard boot pricing varies depending on brand and model. Entry-level boots can be had for around $100, with high-end boots running anywhere from $250 to $450.