Below are some links to some great guitar tableture sites. Some of these sites have lyrics and chords which is a great way to learn to play and sing your favorite songs. These sites are a great way to supplement your regular guitar practicing routine.
 

http://www.guitaretab.com/
 

http://www.chordie.com/
 

http://www.guitartabs.cc/
 

http://www.guntheranderson.com/
 

http://www.tabcrawler.com/
 

http://www.ultimate-guitar.com/