Its been a while, but I believe the Sons of God were angels, who came to earth and had children with human women. The story is found in the Book of Enoch and the Book of Jubilees, which didn't make the final cut in the current Bible, although they are referenced several times.
I'm not real convinced on the wife of Yahweh thing, either. Some sects may have believed Yahweh had a spouse but I don't think it was a widespread belief.
