I found this nice channel of the Massachusetts Institute of Technology, presenting educational material for free. http://www.youtube.com/user/MIT
There are a wide category of courses included. Maybe you find a topic that always interested you but you didn’t find much info about it
I didn’t check all the courses (way too many of them^^) but I have to say, it seems mostly high quality to me (there was one video that seemed to have been uploaded in a bad way or something, which was really low quality, but all the rest was just fine) and the explanations are well understandable.
The greatest benefit of this: You get to follow along at your own pace, and really absorb the material.
[rant]
As a student in an actual college, you’re restrained by the limits of time: There are 4 main tests (usually), for which you have limited time to prepare, and then there are all the other classes you’re taking that semester, so you have to ration your time and attention between all of them.
It’s a really crappy learning environment, because you never feel at ease to really delve into a subject, and truly “learn it”.
… If there is one thing you really learn in college, it’s how to pass a test (and your social security number).
[/rant]