http://www.udacity.com/ <- cs classes
http://coursera.org/
http://www.khanacademy.org/
http://www.khanacademy.org/#biology
http://www.khanacademy.org/#computer-science
UnCollege.org has a nice collection of online resources, including a lot of computer science resources: http://www.uncollege.org/resources.
- MIT Open Course Ware: http://ocw.mit.edu/courses/#electrical-engineering-and-computer-science
- Google Code University: http://code.google.com/edu/
- Stanford's Education Everywhere: http://see.stanford.edu/see/courses.aspx
