building performance engines, where can i find good info?

ive been looking around on the internet, different options and such as far as how to build my engine. Ive got many questions as to what i should do as far as compression, cams, boost, all kinds of stuff. I've found books on the subject, but I dont want to end up buying a book thats just going to try to sell me things, I want something informal so I was wondering if anyone knows what I should get or any good websites that have good info. thanks