Learning Rock Band Songs

The songs in Rock Band are great and since I have access to the music with and without drums, I think that I'll concentrate on some of the songs in the game as the first song I'll try and learn. Rock Band organizes the songs in order of difficulty, and while those difficulties might not match the difficulty playing on a real kit, the song list should still be a good guide of songs to try and learn. I'm sure it will be no easy task.