For young kids, you can't beat Signing Time videos for vocabulary!
If you really want more, here's an online program: http://www.signingonline.com/
http://www.ASLpro.com is also very useful, too.
I'm an interpreter and everything I learned, I learned from the Deaf community. So if you can get to know some of the people in your area who are deaf, your lessons will take on a life of their own. Grammar, syntax, etc can really only be learned from the masters--the Deaf themselves.