Other
Guitar Lesson World
An in-depth look at guitar playing. Includes exercises, lessons, resources, and much more! Whether you are a beginner or more advanced, this site is definitely worth seeing.
Cosmo Learning
Cosmo Learning: Courses: Guitar Music Theory
A series of 16 video lessons that teach basic guitar theory. Lessons discuss intervals, perfect and diminished notes, and octaves. Videos vary in length.
Other
Play Guitar: A New Method for the Study of Guitar
If you would like to learn to play the guitar, you will want to visit this website. These online lessons guide you through the basics of learning to play the guitar. This site is also available in Hebrew.
Other
Ruby Cliff Computing: Learn Guitar Theory With Virtualoso Guitar
This is a fantastic site that teaches basic music reading, especially as related to the guitar. Although the site is a promotional software site, the trial version is excellent by itself.