a fellow writer
I am also writing a novel for the teen market in the US. I've had a lot of past experience with the Deaf Community. (Still learning ASL!) My book is Science Fiction, though. I've just started (3 chapters).
I actually went to a mainstream middle school with a separate Deaf program for the Deaf kids with an ASL Deaf adult teacher. I ran into this teacher at my community college YEARS later! He didn't know who I was, of course, but I remembered his face.
I also had a deaf girl in my math class in high school. (My high school didn't offer ASL.)
I've visited the state school for the deaf in CA and I live near the one in WA.
I have an uncle who is a professional writer. 
Good luck with your project!
I studied Spanish and ASL in school and college. I'm doing some home studying again... my signing is still kind of slow and my memory is trying to sink it in my thick skull!
I agree with the other poster that ASL "is not just like other languages"--it's beautiful and complex. 
JM
