G. K. Chesterton was once asked what one book he'd take if he were stranded on an island. He said a book about shipbuilding.
Other than that, and the Bible... this is what I'd suggest you take: Tim Keller's new The Reason for God.
If you read one book in your LIFETIME, THIS SHOULD BE IT. I know this sounds like I'm exaggerating, but this really is the absolute best book I've ever read at interpreting the Gospel for our culture.

Keller shows the reasons why only the Gospel can address the needs of contemporary people, why belief in the Gospel is eminently reasonable, and the absolute difference between religion and the Gospel. Keller is a very "plain-spoken" author, but some of the passages in it are so beautiful and compelling you feel as if you are reading poetry. That's because the beauty does not come from the eloquence of the words, but from the clarity of the Gospel.
Here is one sample passage (which you must read in context to get the power of it):
The repentance that really changes your heart and your relationship with G od begins when you recognize that your main sin, the sin under the rest of your sins, is your self-salvation project. In both our bad deeds and our good deeds we are seeking to be our own Saviors and Lords. We have alternative trusts and 'gods,' even though we do not call them that. We try to prove ourselves by our moral goodness or through achievement or family or career. Even diligent involvement in church and religion may need to be repented of once we understand that it was all a way to put God in our debt... (p. 234)
The Gospel is about turning from your worshipping of and being rescued by other things to worshipping and being rescued by Jesus. When you understand the Gospel, it creates such an intense love for and desire for Jesus that you want to spend your whole life just getting more of Him.
One depressing thing about reading this book is I realize how little many "evangelical" churches preach the actual Gospel (seems to me). I'm thinking even of those places that have high "conversion" numbers. People are moved to pray salvation, come-to-Jesus prayers and get baptized, but you don't see a people falling in love with Jesus. And I've heard a number of those places give invitations where the actual run-to-Jesus-who-was-substituted-in-your-place-Gospel was never really explained. Instead, "accepting Jesus" was presented almost as if it was some kind of sacrament that would make you closer to God and fill in that missing piece in your life. Most "converts" come to Jesus as a "way out of hell" or a "path to a better life," but not as a beautiful God with whom we fall in love with. In these converts you see little passion to worship and really know Jesus. If our converts are not passionate about worshipping Jesus, what are we converting them to?
And it starts with us leaders, it appears to me. Sometimes when I listen to successful church leaders I get my mind filled with new, cool ideas (for which I'm grateful), but they don't make me fall in love with Jesus more. They, and we listening to them, appear to be more enamored with success at growing a church than we do adoring the Jesus of the Gospel.
Sorry for the tirade. But on a separate, much lighter note, there is a ridiculously hilarious (new) blog called "Stuff Christians Like." Check out #'s 108-106 (Summitters, we get mentioned in 107)... 101, 100, 26... 98... 90, 89... 68 67, 60... especially 31... Heck, THEY'RE ALL GOOD. WARNING: YOU WILL WASTE AN HOUR OR SO IF YOU GET ON THIS BLOG.