Dan Brown says that the best teaching books are driven by personal stories as opposed to abstract theories and generic technical illustrations:
When I read about an educator in the field, experimenting and developing her craft, I'm engaged. To me, the best professional development (PD) books are also steeped in the narrative of teaching. I think there's some human nature involved here; telling stories is at the soul of the human experience.
As someone who receives a lot of education books, I have to admit I’m very sympathetic to this. I love to hear that personal voice coming through—and dread slogging through seemingly endless bulleted lists and diagrams. I have also been known to argue that many education books, with their closely-packed type and wide pages, seem almost designed to discourage you from reading them cover to cover.