People who are rusty (and that's all or most of us) can start at the very beginning to get back in the swing of things. That's what I did and was amazed at how many little rules about math I either forgot or never learned (and I considered majoring in math in college).
If you start at the very beginning, you'll zoom ahead as it all comes back to you.
Khan Academy is a mixture of very short videos and exercises (usually 4 questions to test your understanding).
Sal Khan makes math fun and easy to understand.
Looks like a cool site.