Ideally, in addition to a manual (or better yet, an official Ford $hop manual), you're going to need hands-on experience like blk92stangg said. Maybe you could find a really cheap or even free 302 to take apart and get familiar with. I did that twice along with tearing apart countless lawnmower engines and playing with model R/C engines before I built my first 302(sig).
I cant remember the name exactly, I think its How to Rebuild Smallblock Fords or something similar is a pretty comprehensive book on just Ford 260/289/302s. Its fairly old so it doesnt cover any roller cam engines, though.