FF Bruce, The Canon of Scripture
Michael Kruger, Canon Revisited
Craig Blomberg, The Historical Reliability of the Gospels
This book was recently updated and one of the best out there on the subject. Jason and I studied under Blomberg but that isn't why we recommend this book. We recommend it, because its excellent scholarship. Blomberg is always fair and clear. He goes over many issues like supposedly contradictory passages but his main concern is demonstrating the gospels do present an accurate view of who Jesus really was.
Richard Bauckham, Jesus and the Eyewitnesses
I have heard this one is really good, and if serious scholars who question the truth of the gospels respect it - it must be good.
One of the foremost experts on NT manuscripts these days is Dan Wallace.
This is a great summary article of the major issues and some great recommendations for introductory books on the subject.
Dan Wallace also has an extensive blog that goes into a TON of nitty gritty.