To get college credits, you of course have to pay. But if you simply want to learn the material, the ONLINE EDUCATION DATABASE can help. Find there “236 Open Courseware Collections, Podcasts, and Videos.” Plus they tell you how to locate more, using the sites they list under Archives. Which sites are VAST. In other words, the process of putting all human knowledge onto the Internet is well under way, and the little chunk of human knowledge you want to put into your mind and memory is probably lurking in there somewhere.

http://oedb.org/library/features/
236-open-courseware-collections