There are already some great references. My favorite is Misquoting Jesus. It's well-written, well-researched and well-documented, without reading like a dissertation.
I attended Baylor undergraduate, and their curriculum requires a semester of Old Testament and a semester of New Testament. In addition to studying what the Bible is and how the Bible came to be (which was an EYE OPENER to me), we were required to read Thomas Paine's Age of Reason.
Age of Reason was written in the 1790s but reads as though it were written yesterday. (You might want to start with his analysis of the New Testament. It's more fun and gets right to the heart of things quickly.) I think it's brilliant and even in many places exceptionally witty. He does an incredible job of pointing out the irreconcilable contradictions between the four Gospel accounts and how no jury could reach any conclusion, much less one "beyond a reasonable doubt", if those four accounts represented witness testimony of ANYTHING in a trial.
Re: Paine's wit, here are a couple examples:
After mentioning that the author of Matthew woke up all those saints and prophets when Jesus died and the temple veil ripped, Paine adds that he could have at least extended the courtesy of putting them back to bed. Seriously, this was the zombie apocalypse, and there's nothing in the Bible that tells what purportedly happened to all of those people who were brought back from the dead.
Paine points out that in Matthew, an angel purportedly appeared to Joseph in a dream and told him to flee to Egypt with Mary and baby Jesus because Herod was going to kill all males under the age of 2. Paine then how inconsiderate it was for Joseph, et al, not to give the heads-up to Jesus' cousin John the Baptist...and how fortunate John the Baptist was to have survived Herod's infanticide without the headache of making a trip to Egypt.
I've also found that having a crystal clear understanding of the inconsistencies between the four gospels is the most effective tool to use if someone is defending the Bible as the inerrant word of God. The gospels are the cornerstone of Christianity, so any holes they create or gaps they don't fill are in turn significant problems for that faith. The rest of the new testament is letters from Paul and pseudepigrapha (forgeries attribited to Paul) plus apocalyptic Revelation.