The Lost Sayings of Jesus by Andrew Phillip Smith

This is a SkyLight Illuminations book (or at least that is who printed the copy I have). They actually have lots of interesting looking books including one about the Book of Mormon.

The Lost Sayings of Jesus: Teachings from Ancient Christian, Jewish, Gnostic and Islamic Sources-Annotated and Explained

This book is a very easy and interesting read. He explores many different sayings attributed to Jesus and commentary about them. It is fascinating to read all the varied quotes attributed to Jesus. There are so many early Christian writings that I am unfamiliar with. Many were used in this book. It also has a few pages from forgeries/hoaxes and other traditions.