Not sure what you're looking for, but here's how I see it. End Product (Hebrew-Aramaic Scriptures: Genesis - Malachi). This I view as important evidence. After reading through the individual books, you might wonder: Where did these come from? What can we learn of the authors? Under what conditions were they written? What were their purpose then? What are their purpose now?
Is this not how the secrets of DNA and RNA were unravelled (Watson & Crick)? They had the finished product, now they had to work out how life functions are controlled by and from the nucleus. So what would be necessary in this case would be to reverse engineer the language of the Biblical texts to see how and why they were written and why they were collected? Here one can make use of different tools: Textual criticism, linguistics, internal considerations (grammar, word studies), external considerations (archaeology, history, related texts), related languages, inscriptions, etc.
Definition: Textual Criticism deals with the nature and origin of all the witnesses of a composition or text, in this case the biblical books. In the course of such an inquiry, attempts are made to describe how the texts were written, changed, and transmitted from one generation to the next.
Fact: Monotheism cropped up in a predominantly polytheistic environment. Why? How? When? We have many pieces of the puzzle. Using above mentioned tools, we can start putting the pieces together. The picture that is starting to form is still imperfect, many gaps still, but it is much clearer now than it was a hundred years ago. So you don't have to look too far for the evidence. It's right there in front of you.