Harmony Central - A really cool site that covers just about everything guitar.
Mega Guitar - An online store/portal to all things guitar.
Cyber Fret - One of the internets best online guitar lesson archives.
Kronosonic - The international society for creative guitar and string music.
My Guitar Workshop - Provides guitar lessons, instructions and music theory for all level guitar
players. Articles, software and downloads, tabs, all the guitar chord diagrams, scales and modes can be
found in an easy graphical displayer.
AudioHarmony - Composer and writer Mike Matta's portfolio site. He's an old bandmate of mine
from UMass Lowell.