I have be playing around the guitar for number of years. Recently I browsed around the net looking at different sites. There are tons of sites for anything from beginners to professionals, acoustic to electronic.
I did find a number of interesting sites. While this site does have paid memberships, they do have a bit of stuff for free:
http://guitaralliance.comI also liked:
http://www.guitar.co.nz http://www.reggieband.com/flash_guitar/http://www.harmony-central.com/Guitar/Lessons/