Well the answer is Anything.
How much you get out of it depends on your approach to learning a song.

Advice, things that inspire you and also challenge you.
Last edited by Slashiepie at Dec 17, 2011,
Lol you're gonna have to give a few more details than that. How do you expect people to recommend you things without you giving any indication of what you can actually play at the moment or what style of music you like?
Learn a song that challenges you. Even if you can only play it at half speed