http://commtechlab.msu.edu/sites/aslweb/browser.htm
This one allows you to look up words and it will play a video to show you how it's "signed"...you need Quicktime.
http://where.com/scott.net/asl/abc.html
This one shows us the alphabet....I'm a visual person and need to see how it's done as opposed to just explaining it with words.