I have found the "Gun Digest" Firearms Assembly & Disassembly Manuals extremely helpful. I have them for centerfire rifle, shotgun, semiautomatic pistols and revolvers. They cost around $25.-$30. each and are well worth having.
I also have Stephen Camp's most excellent Hi Power manual.
I don't have, but would really like to have Jerry Kunhausen's 1911 manuals someday as well.
In the interim, a good buddy of mine is an "advanced tinkerer" and is available for help and the internet has been invaluable.
I've rebuilt two rifles, an M1 carbine and a Marlin 1895SS, done a trigger job on a Ruger GP100, and am rebuilding and refinishing a S&W model 37 right now.
I've also done simple stuff like change out recoil springs, sights and other parts as well.
The hardest part is doing the first one. After that, confidence builds and stuff makes more sense as you get into it.