I came across this web tool for learning to play a song. I'm the type of person who buys sheet music that's too tough for me to play, and I can't sight read sheet music well. This has been pretty helpful.

http://plern.darkinertia.com

Right now it's just a way to visualize which keys to play and when. It's still under development and there will be sound at some point.

This site has audio now. Now you should be able to hear the song on the screen.

And now you can import midi files and extract the sheet music out of them.

http://www.darkinertia.com/plern/