I am a University of Utah mathematics major and I love the word FREE. (cheap is good too)
I don't have a lot of money so any Free resources to help me study are worth it to me. Since I know a lot about mathematics that is what I will be posting here.
The key to Mathematics is Learning, Practicing, Learning, Practicing, and sometimes it goes in the opposite order: Practicing, Learning, Practicing, Learning. But either way a good resource to me has a bit of both: they teach you how and why you do something and they make you do it as well. A really good resource will teach you how and why, make you try it, and then will show you why you got it wrong and what you should have done, and then make you do more problems of the same type. So then, without further ado, here are the resources:
Paul's online notes (type it in google it will be one of the first to pop up)
his notes are free, come with worked out problems, solved problems, and homework problems, he has helpful downloadable review sheets, and I used him all throughout my Calculus courses.
he does from college Algebra to Differential equations.
Someone give this guy a medal.
she loves math (once again you can type this into google)
This website is great for review of junior high, high school mathematics. Her way of explaining simplifies some confusing concepts and her pink boxes are great! They tell what the rule is, give an example of how to use it, and explain in words (instead of just mathematical symbols) what you are doing.
This website, however, is lacking problems for you to try out.