Free guitar lessons (In Portuguese). This is my favorite lesson site. You don't need to know Portuguese to learn from this site due to their format. Lessons are detailed with videos, tabs and chord charts. And as an added bonus you may learn some Portuguese.
Three Chord Guitar
Mojo says "In the words of the great Vince Gill, “it’s what you give away!”"
Chordie is a search engine for finding guitar tabs, guitar chords and lyrics
An interesting combination of videos, tabs, chords and lessons.