It would be very difficult on a forum like this to explain all of the things you may need to know about Deaf culture. I think a better approach would be to read several excellent books on the subject of Deaf culture. A few I can recommend to you are:
Deaf in America: Voices from a Culture (Paperback)
by Carol Padden
A Journey Into the Deaf-World (Paperback)
by Harlan Lane
by Oliver Sacks
I suggest starting with this last one listed.