Most people listen to what friends, circle-mates, or their teachers suggest they read some few of us branch out on our own and just look for books. I would be classified as one of these. When I first began researching Paganism and Wicca, I had no real direction. I just read everything, the good, the bad and the really scary. Today I have certain criteria for what I read.
Original thought is all well and good, but research is essential.
If the potential book does have a Bibliography I check to see what it contains. It is possible, by checking the sources, to tell if the author is traveling down the same old tired road or has some degree of original thought. Research is important. Imaginary history seems to be a Pagan trait these days. Historical Allegory has its place.