How to read the guitar chord diagrams:
Easy G guitar chords
I have selected some chord positions that are especially suited for acoustic and electric rhythm guitar playing (as opposed to lead/solo guitar playing).
If you are looking for a beginner's book on how to play guitar, I can recommend Learn To Play The Guitar (by Phil Capone) until my own book gets done. Read more about my books and recommendations here.
Here are the quick links to all the G guitar chord pictures:
G guitar chord chart