You're basically going to have to exercise your own discretion in what you want to read. The opinions of "scholars" vary so widely on the topic. In the article I link below, these scholars say by means of a ballot that Yeshua only said 16% of what is attributed to him in the Bible in this so-called Jesus seminar; others get into the so-called "Gnostic gospels (which were deemed uncanonical by the church because "they weren't consistent with the four main gospels).
Here's a link to an article that talks of the very topic you are discussing, authenticity:http://watchtower.org/library/w/2000/5/15/article_01.htm
The article takes a look at the historicity of the accounts in the Bible. Hope that is of benefit to you.