Guitar Player Repair Guide by Dan Erlewine
This book is an easy read. It is more or less the bible for repair.
If you are really serious, there is a
DVD series that lets you see it hands on.
Electronics, wiring, and pickup replacement is easy with the
Standard Book of Wiring Diagrams.
The diagrams are drawings of components rather than schematics. Anyone can read it.
Trade Secrets will save you a lot of time once you've gotten started.
The most important thing to do is to practice on scrap or beater guitars from the flea market. They'll be starting up again next month in your neck of the woods. Buy a few and practice.
BTW, Luthiers Corner is cool. But Setup and Repair is where most of the repair info is. Builders are only sometimes repair techs. No offense to the fine builders who post here.