The subtitle to the book is Unearthing What I Believe and Why It Matters. This is a pretty accurate description of Harris' purpose in writing. The book is about the importance of good doctrine. There are a lot of good systematic theologies that will provide readers great, solid biblical truth (Wayne Grudem's being my favorite). And although I think that reading a great systematic theology is something everyone should do, I really like Harris' approach.
Harris takes a lot of time to weave his personal experiences into discovering good doctrine. So, instead of another theological tome, we get to understand Truth through Harris' experience. It gives the book a readability that is rare for such a serious matter as doctrine.
My favorite chapter in the book involves the author's father. In this chapter, Harris tells the story of how Jesus saved his Dad. We follow his father through his years as a rebellious, hippie troubadour. God saves him in a "chance" meeting on a California beach with two nameless guys who are talk to people about Jesus. It is a compelling story.
I highly recommend this book. I think that it will be especially useful to people that are young in their walk with the Saviour. It is a good introduction to basic, biblical doctrine told in a way that keeps the reader engaged from beginning to end.
You can pick up a copy here.