Did authors know their predecessor's work let alone their contemporaries? And how?
Thanks!
There are some 60-70 individual books in modern Christian canons. The authors of the New Testament books/epistles all certainly knew the works that constituted the Hebrew canon. The big debates are all going to be over which works authors knew within their "own" canons (that is, whether authors of books in the Hebrew canon knew other works that were eventually placed within this, and the same for the New Testament).
The authors of the gospels of Matthew and Luke are unanimously agreed to have relied on the gospel of Mark. The NT epistle 2 Peter explicitly refers to the epistles of Paul:
our beloved brother Paul wrote to you according to the wisdom given him, speaking of this as he does in all his letters. There are some things in them hard to understand...
It's widely agreed that some of the pseudepigraphical works in the NT -- e.g. those ascribed to Paul -- took over material from the genuine Pauline epistles.
As for the Hebrew Bible, it often gets quite complicated. In general, the later the book was written, the more likely it is to have had knowledge earlier works which had become authoritative (some of these had probably been around for 300-400+ years). But, for many other works of less certain dating, the debates as to knowledge of/dependence on other works are so complicated that it's hard to succinctly summarize them here (I applaud whoever attempts it, though). I hate to be lazy and refer you elsewhere, but you might be better off just searching for things like "redaction criticism" or "intertextuality" of/in the Hebrew Bible.