The Khan Academy is one of the best finds for students. These are Youtube video lessons and there are approximately 2,100 videos. Watch, Practice, Learn Almost Anything for Free--
It started with the founder, Salman Kahn, who began all this when he was tutoring his cousin in math. They did not live close, so he taught her using a tablet and the computer. First he put them up on You Tube, and then they became very popular. Now, they have over 41 million views.
The subjects cover everything from arithmetic to physics to history. I am going to start using this for Algebra and see if it helps get my son more interested.
Khan even has great business and finance explanations. This is a great resource for anyone wanting to know more, things you may have missed in school are easily explained. There are worked examples for math problems, chemistry, biology and physics.
Take a look and see if you can use some of these with your kids or even for yourself. Khan Academy
Salman Khan with Bill Gates before Khan's talk at this year's TED conference. Photo: Flickr.com/JRandomF