Many colleges have started putting their older classes on-line for free. You don't get college credit but you get the information you need to learn something
new.

MIT has more than 2000 courses. Some have video, audio, notes and outlines.

Other places to look

webcast.berkley.edu
ocw.nd.edu - Notre Dame
open.umich.edu - University of Michigan
ocw.tufts.edu
Carnegie Mellon
Wikiversity
Wikibooks
Creative Commons Education
flatworldknowledge.com