You're definitely headed in the right direction. Just the fact that you're interested in music theory shows that you are. Most guitarists these days couldn't care less and just start banging away on one-finger drop-D power chords.

If you're looking for a book on music theory, I'd recommend Scales and Modes: In the Beginning by Ron Middlebrook. It explains all the terminology of scales, intervals, and etc from a guitarist's point of view. It goes from the basic to the advanced, so it should get you started.

One other thing you might want to do is seek out a knowledgeable teacher. (like Skee1, hahaha!)

If you have any specific questions about theory, we're here.