since you are interested in early church history and archeology that proves it up, you really must read the book.
In addition to the central thesis, (eg, that the dynastic family relations of Jesus and John the Babtist made them logical and palatable purveyors of the messianic movement in a time of Jewish ferment), it has some fascinating scholarship and information about locations of burial chambers and burial ossuaries found there.
Most folks don't even realize that Jesus had a number of brothers because the New Testament books sort of gloss over them and the names are so common that the references are mixed up.
Likewise some interesting stuff on the relationship between Mary and Joseph.
I couldn't put it down.
Well, that fact has been debated since the earliest days of Christianity. The NT does refer to "brothers", but a) in Semitic usage, brothers often means close relatives like cousins and not always uterine brothers; and b) some of those putative "brothers" of the NT have different mothers, so they can't be uterine. Also, c) it's a little nonsensical for Christ to give his mother to St. John from the cross if she has living sons to care for her.
There is an old tradition in the East that Joseph had children from a previous marriage, but as far as any other children of Mary, that has yet to be demonstrated. Certainly the Church has always repudiated that belief in the strongest terms.