Bruce Metzger: On the Methodology for comparison of religions
http://web.archive.org/web/20071106001112/http://www.frontline-apologe tics.com/mystery_religions_early_christianity.htm
This page I recalled posting in a discussion of the "pagan parallels" theory of Christian origins which forms the first third of the Zeitgeist movie. The page itself went down but I've retrieved it.
It's quite fascinating reading.
http://www.historyversusthedavincicode.com/
History vs. the Da Vinci Code