Right, easy to do. Get the songs in MIDI format (there are numerous sites around that will have them. One good site, with people arranging the music so it sounds better when played as a solo is: http://www.squaresound.com/arrangements.html)

The second thing you need is a program that will take the MIDI's and turn them into sheet music that you can print off. I use Sibelius, but that's overkill if you just want it for making the sheet music from MIDIs (it's a really complicated and advanced program that a lot of musicians will use to compose everything from a brass quartet piece to an opus for a full orchestra).

I think that Finale Notepad should do the trick: FINALE NOTEPAD

Gimme a bell if you can't get it to work. In fact, let me just check if you can import MIDI's, and then I'll give you the link.

Also, if you want things from the Squaresound website, you'll need Sibelius Scorch (another free download): http://www.sibelius.com/products/scorch/index.html