The Guitarist's Music Theory Book by Peter Vogl is the first music theory book designed for guitar by a guitarist. The book explains music theory as it applies to the guitar and covers intervals, scales, chords, chord progressions, and the Nashville Number System. The included Audio CD features examples of all the music in the book and also an ear training section. The Music Theory Book was written to help all guitar players achieve a better understanding of the guitar and of the music they play.
As a beginning guitarist, and having no musical background whatsoever, this book really helped me grasp the fundamentals of music theory. It's an excellent introduction to the world of music theory, touching on notes, scales, chords, chord progressions and how they relate to each other. Although the book does go on a few more complicated tangents at times, it didn't really bother me as I viewed it as an introduction to more complex music theory and an anchor for me to further improve my musical knowledge once I'm ready for it.