Here are some books relating to guitar and music that I recommend. Just remember not to let books replace listening and learning in person.
Training and philosophy:
Zen Guitar - Philip Toshio Sudo A great book about cultivating and sustaining positive attitudes with respect to guitar training.
Effortless Mastery - Kenny Werner
The Inner Game of Music - Barry Green
On Practicing - Ricardo Iznaola Direct approach to effective practicing.
For Guitar Players Only - Tommy Tedesco Sightreading, technique, attitude, studio insights, and guitar related humor.
Blues Guitar - Greg Koch Good beginning blues guitar book.
Playin' the Blues - Robben Ford Very musical examples.
The Real Book
Creative Jazz Improvisation - Scott Reeves
Jazzology - Robert Rawlins and Nor Eddine Bahha
Jazz Guitar - Jeff Schroedl
Getting Into Gypsy Jazz - Stephane Wrembel Django style jazz
Pumping Nylon - Scott Tennent
Kitharologus - Ricardo Iznaola