I like Youtube for getting the basics of what a guitarist is playing. I'd advise sticking to folk-y music, because it's easy to see what's being played.
For a one-stop shop for tunes, try U2. Sounds very complex, and the arrangements are. But the tunes are generally just tow cords. Listing to them gives good practice on the song, the cord basic for (virtually) all songs and an insight into the possibilities of music against a simple cord progression.