OpenCulture is a great collection of links to resources about culture and learning. If you’re looking for online courses offered by top universities worldwide, check out their 1200 Free Online Courses list.
The collection of links represents over 30,000 hours of audio and video lessons. Even at 10 hours per day, it’d take you over eight years to get through it all. Plus there are other lists of freebies — MOOCs, movies, audio books, ebooks, K-12 education and more.