If you haven't checked this web site out, you are missing out. I am a student at UCM in Warrensburg, MO and just recently heard about this web site through Forbes magazine. It was created by a guy who started making tutorials for his nephews using his iPad or something of that sort. It caught on and is amazing. There is content in the areas of Math (basic-calc.), Biology, Gen. Chem., Org. Chem., Physics, and Astrology. From what I have looked at so far, it's pretty good stuff. He goes into great detail, but is suprisingly very easily understood. I wish I had a little more info for you but I will post the link at the bottom of the page. There are tutorials galore and even a practice section that tracks your progress, however the only area in which you can practice at this point is mathematics. I hope to see more practice sections in the future.
For students: Great reinforcement tool and refresher. I myself have looked pretty extensively at the Orgo section just to brush up on mechanisms and functional group properties for my Adv. Biochem class. Very helpful.
For Educators: endless possibilities, it could be used as a secondary source for sure. He also has a page available in which you can post ideas for future content and lend your personal expertise so that he can continue to put new, knowledgeable tools in his library.
The best parts of the site as a whole is that IT'S FREE, and as he is explaining whatever the topic maybe, he is working it out utilizing multiple colors to group concepts and key elements of the lesson. It truly is a must see and I hope you all can benefit from my find and help this project grow.