Watch the Street Theory for Guitarists online guitar lesson by Jeff Scheetz from Street Theory for Guitarists
Hopefully this course has not only given you a great bunch of guitar theory subjects to dig into, but also gave you the desire and confidence to go even farther down the theory path. The journey can be as long and deep as you want it to be.
Theory is almost endless if you choose to get into all the possibilities. However, what I call "Street Theory" will give you the essentials of what you really need to know as a guitarist and help you develop your own voice! So, good luck on your theory journey!