I love the youtube videos created by CommonCraft.com. They make very simple but effective videos in which they explain all sorts of technological tools.

This video is an example of the kind of work they do. If you are interested, you can visit their website and check out all of their tutorials.  They now even make custom videos for anyone who is interested. If I I had the funds, I would hire this company to make all different kinds of tutorials for my students.

http://www.commoncraft.com/blog