The Jesus Manifesto by Leonard Sweet and Frank Viola
For just a short time the book can be purchased at a 45% discount on Amazon.com. Currently the book is #6 in terms of sales out of the 7 million advertized on Amazon. The book lends itself for small group discussion, both among new Christians and established believers. With a very readable style, and a content worthy of multiple rereads, it is a can't miss for your library.