One of the most accessible resources on Josephus and the Testimonium Flavianum has always been a paper delivered in 2000 to the Society of Biblical Literature conference by Alice Whealey. For years it sat at http://josephus.yorku.ca/pdf/whealey2000.pdf but this link is now dead.
Rather than lose it — I needed to refer to it this evening and couldn’t find a copy! — I’ll place a copy on this site. Where the SBL papers that used to be on the josephus.yorku.ca site now are I do not know.