In this XXI century the resource you need is called GOOGLE. It will take you to really good sites, where you'll find all you need.
don't buy a book, unless you plan to be a guitar tech, in which case maybe you should take classes instead.
action/intonation/truss rod adjustments on electric guitars are EASY once you understand the concepts. (I hope you meant electrics, right?)
passive circuitry is fairly easy too. especially with nice diagrams available online for mod-monkies like me, who can't read real electrical diagrams.
I mean, I still can't memorize Ohm's Law and still don't know why POT's have 3 lugs, but I've replaced pickups, installed phase-switches, coil-splits, shielding and such. It really doesn't take an electrician, much less an engineer.
Passive circuitry is NOT (strictly speaking) "electronics".