It seems to me that you have to do the right thing, which is to innoculate your friend from the Witness influence, no matter the consequences for yourself. I agree with those who say you should do it in small does, as particular issues come up.
I think that giving him Ray's book may be too much input at this point, but may be quite useful later. When particular topics come up, you might refer him to a relevant website, such as FreeMinds, Watchtower Observer, SilentLambs, or this discussion group.