Once you've created your account, have a look around. There are three great things to do that will help you out and help us out:
1. Ask a question (or even more than one) - this is probably what we need most right now
2. Answer a question - share your knowledge!
3. Upvote and downvote - the votes are the "currency" of the whole system, and they're what keep the whole thing going. This brings the strongest answers to the top. And, of course, everyone loves getting, erm, internet points ;-)