Intake and Exaust,
More air IN, and more air OUT, is always the best to start.
Chiltons, Haynes, and most of the Hot rod/5.0 mags put out small block how to books and videos in some cases.
The regular car manuals will have all the torque specs you should need while working.
Its not real hard, with a little luck.
The only thing i didnt trust doing was torqeing, shimming, and setting the main berings.
Had a friend do it that had more experience.
Rebuilding an engine the RIGHT way, take a lot of time and MOney. There is A LOT of stuff to do it right.
Basicly read everything you can get you hands on, check out the 5.0 mag sites for their tech articals, google a bit, and keep reading till you feel comfortable and have enough saved to do it right.
Thats the best i can give for advice.
(one more thing, look into a Short block, that is already done right, it can save alot of time and money, not to mention some hidden bugs you may not even know about till after its apart, that will cost more down the line)