The apocryphal Jesus traveled a fair bit, led a religious sect, was a somewhat known public figure, and was publicly executed with some amount of fanfare. Basically anything contemporaneous would be a good start. Given that multiple of the supposed references to him refer to multiple people by the name, it seems far more likely that a variety of Jewish men named Yehoshua were after the fact agglomerated into one historical invention.
At this point, someone needs to do a whole lot of research. I think that "someone" is you. I'm not going to do it for you.
From what I've gathered, scholars compare the various pieces of evidence for consistency with what else is known. That's why they know that the canonical Gospels weren't written until the latter part of the first century, for instance, and there is one lost text that three of them derived from.
"it seems far more likely that a variety of Jewish men named Yehoshua" -- ok, to you. I don't care to argue that because I'm not a scholar of that period. I suspect you're not, either.
