Are there any online schools for learning american sign language?

I don’t know of an online school but you may want to check out this site, it should get going in the right direction until you can locate one: http://www.aslpro.com/
It’s a video dictionary of ASL, click on which dictionary you want
(main, religious, conversational, or ASL for babies), click the word you want and it’ll show you a video of how to do the sign.