The issue of canon is one that comes up occasionally here in Colombia. People will ask about why our Bible has fewer books than the Catholic Bible. Another common perspective follows a Dan Brown-like view that the canon was something imposed in the Council of Nicea in A.D. 325. I frankly always felt a bit ignorant about canon, or perhaps thought that nothing new could be said, but I was wrong. I wanted to point you to a lecture series by Michael J. Kruger on this topic. Kruger is one of the leading evangelical scholars on canon. His style is very easy to follow, and he has obviously devoted much time to distill the issues on this complex subject. The second lecture was the least strong in my opinion because he relied a lot on Covenant Theology, but the other three are excellent and enlightening. In today’s world, understanding something about canon is no longer a luxury. You can find the lectures here:
I haven’t read his book yet, Canon Revisited: Establishing the Origins and Authority of the New Testament Books, but I’m sure it would be very good as well.