http://www.sosmath.com/
This is more of a teaching tutorial showing written examples of your basic algebra all the way up to the second semester or so of a differential equations course. If you're trying to actually learn the stuff I wouldn't suggest this site. It's an awesome supplement to any course though, and that's where it becomes fairly functional - to get two sides of the material explained in different ways. Anyhoo back in the day it helped me out.
Hope this helps...