I'm a mediocre player and I'm fine with that - but I get a lot of satisfaction out of getting a good strum going and hitting most of the chords while singing with other people. Chordie is a fantastic resource if you like to play in front of your laptop.

Not only does it give you chord diagrams next to the song, but you can instantly transpose a song to any key you want from a select box. I also use the "auto-scroll" feature to save me from stopping a song half-way through to move the page down.

At the risk of revealing myself as an Old, here's my Chordie song book from Delicious. Many of the links have been transposed to a comfortable key for me. (if I ever start a band I'll call it GC/DC).