Have you ever skied before? Snowboarding became absolutely huge for awhile then sort of petered out a bit, but still has a presence (at least at the resorts that usually go to). I started skiing when I was 7, switched to snowboarding when I was 16 or so, and switched back to skiing when I was 21ish (I'm 27 now). I still have my snowboard and use it occasionally. I'm not going to try to tell you that one is better than the other, 'cause that ain't the case. You may hate skiing and love snowboarding, or vice versa, or hate love/hate them both.
For me, snowboarding had a tougher initial learning curve, but was easier to become pretty good at (tricks, etc.). Skiing was just the opposite (again, for me, YMMV).
As far as gear and stuff, don't spend any money til you try it. Wear what ya got as far as cold weather stuff, and rent a board (or skis) a few times at a resort. If you like it, and plan to continue doing it, then buy the stuff.
Ski and snowboard stuff isn't cheap, so make sure you'll use the stuff before you commit to buying it.
Have you skateboarded or wakeboarded at all? They are somewhat close to snowboarding (some basic fundamentals apply). One big difference, though, and it's a steep one to get over for a lot of folks. With a wakeboard, you will have most of your weight on your back foot. Doing that will have catastrophic results on a snowboard - you're going to be more centered, if perhaps putting more weight on the foot facing downhill. And that can be a very odd thing to get used to.
Try 'em both, and rent for a few times.
And I've lurked long enough to know that you guys will appreciate this - I'm the guy that's outskiing the yuppies with $2500 worth of skis and clothing, and I'm on used CL skis wearing Carhartt overalls.