I don't share tokyo's view on burton ratchets, but the main thing is to buy from a shop with a good return policy. That way if you buy and try, and they're just not working for you, you can go in and swap them.
I think bindings are nearly as important as the board, which is nearly as important as the boots in a setup. Good bindings will work without making you frustrated, have the right amount of support, and be the right size! Bad bindings can cause you to get really frustrated before you're even heading down the hill...
A couple things to look for:
- toe caps are better than straps, after riding with, I'll never go back
- metal ratchets will tend to last longer without parts elongating and starting to skip
- nice wide ankle straps will tend to be more comfy than thinner straps, given the same amount of hold
Oh man, I think my painkillers are starting to kick in. None of what I just wrote makes sense to me!