Good Luck. I just had my first snowboarding experience last week (after years of skiing) and went back for another go at it yesterday. I bought a pair of R.E.D. shorts that have removable pads and plastic shields for your rear end after my first outing. Definitely worth it to me. I wish I'd had them the first time.

No matter how frustrating it seems the first time, you'll be surprised how much you improve the next time around. Don't forget to bend your knees.