Craig Blomberg, one of our most important New Testament scholars, has written an excellent article entitled "Jesus of Nazareth: How Historians Can Know Him and Why It Matters." The article was posted by The Gospel Coalition.
If you would like to read more by Dr. Blomberg, here are just a few of his books:
The Historical Reliability of the Gospels
Jesus And The Gospels
Interpreting the Parables
Making Sense of the New Testament