Interesting topic.
Be prepared for people to be come squeemish whenever you talk to them about it.
My suggestion would have to be "I Lucifer" by Glen Duncan. (sp?)
It's about satan getting one more chance from god to live a good mortal life.
Satan gets to inhabit the body of a wrighter that has commited suicide. The whole book is like a journal of satans time spent in this body. There is alot of observation about life from satan's point of view, and in general it is just an excellent book. I'm not even interested in satanism or anything, but I almost couldn't put it down.
If you havent checked it out definately give it a read. Enjoy.