The World Lecture Hall is a compedium of links to open university materials. Some include lecture notes, text books and even video. The OCW at MIT is probably the most well known but there are many universities that provide online access to course materials. Want to learn about medicine? John Hopkin's kindly provides some popular courses (Cadaver not included). Notre Dame provides a number of courses focused on the liberal arts. The University of Washington provides Computer Science and Engineering courses. Tufts provides a potpourri of courses, including dentistry.
music files is a neat site I found while looking for information on a classical piece I'm learning on guitar. It seems to predominantly cover classical music but also covers other genres. It has biographies, mp3s, sheet music and so on.