A fakebook is a musicians resource. It consists of simple melody lines in standard notation usually with guitar chords. This site augments paper fakebooks by letting you hear an unfamiliar tune and play along. The tunes on this site are in the public domain. Sheet music is readily availble on the web and in published books. There is no sheet music available on this site.
MIDI provide a ready practice resource. They help you learn new tunes and improve your playing of ones you know. If you use a program like the free van Basco Karaoke MIDI player (below), you can adjust tempo and mute voices to make using these MIDI even easier.
Note: the van Basco player is a Windows only program.