Welcome to the forums!
First thing to do is to work through ALL the tutorials in the online help file. No other process or advice is as helpful, and after you've done this you'll have the answers to a lot of your questions.
After that you'll want to look at how folks have rigged specific characters -- there is some good content provided in the AS version you have, but you should also download the demo for the new AS 6 which contains a whole lot more content to examine (eventually you will want to upgrade to the new version anyway).
There is a book on AS you may want to get -- it's the only one offered by anyone and it's sold by Amazon so you can just do a search there. It's definitely worth having.
Finally you can ask as many questions as you'd like here about specifics -- no one here is shy about answering -- as well as search some of the invaluable threads in the database. There is a goldmine of info here even if accessing it isn't as straightforward as other sources.
(And I'll even put a plug in for my website -- not much now but it will get better:
www.kelleytoons.com ).
