I would say just delve into the online forums, there's a few books you can read that I can recommend (mostly about turbocharging, but that's where the fun is anyways
), and also you can find great articles online on wikipedia and howstuffworks.com (I think?).
Just read read read, and never pretend to be a know-it-all, no one ever knows everything.
Good book:
http://product.half.ebay.com/Maximum...35870QQtgZinfo
Maximum Boost, Corky Bell (seriously!)
Great sites:
http://auto.howstuffworks.com/engine2.htm
http://auto.howstuffworks.com/turbo.htm
http://wikipedia.org