areiser:

Mr. Plotz comments that "the life of Jesus is pretty well-documented".

Besides the bible, what is this documentation? What other texts discuss the life of Jesus? What archaeological evidence is there?

There's not much, really. Josephus, a Jewish historian working for the Romans, makes a very brief mention of him and his brother, James.

The Talmud has a story about Yeshu whose mother was Miriam and was betrothed to a man who was a carpenter. There also is b. Sabbat 116b "Jesus the Nazarene [who] practiced magic and led Israel astray."

The fact that Jesus is an historical figure is not much in doubt. The Christian claims about him (and I am one who makes such claims) are not historically verifiable outside of Christian literature.

There's also no direct archaeological evidence. The closest was the supposed "James Ossuary" (James being Jesus brother and his ossuary had an inscription on it that said something like "Jacob, brother of Yeshua") but it turned out to be a likely forgery. It was tantalizing while it lasted.