Academic Earth and Open Culture offer dozens of courses, text books, ebooks, and ways to educate yourself right at your fingertips!
[Edited: Make sure to read the full terms and agreements, and like most online course sites, do not expect this to act as a replacement for a real-life class unless any specific course you sign up for states it offers transferrable credits. Make sure you know most online-courses will not be recognized as a replacement for any part of any curriculum by credited educational institutions.]
Through Academic Earth, you can take courses in all of the fields below:
Academic Earth offers a variety of Universities, which you can click through below to see which University offers for specific online courses.
Open Culture offers dozens of FREE  online courses,  audio books,  movies,  language lessons,  ebooks, and  text books for your personal mind expansion!
Online courses from Open Culture include the listed topics below:
- Art & Art History
- Classics & Classical World
- Political Science, International Relations, and Law
- Urban Studies
- Computer Science & Artificial Intelligence
- Engineering [Mechanical, Civil, and Electrical]
- Environment & Natural Resources
- Psychology & Cognitive Sciences
- Public Health
Enjoy the over-abundance of free educational resources, and never stop exploring and expanding! And if anyone knows of any other great self-education resources, let me know