Writing a Book

I am thinking about writing a book. I cannot decide if it should be a nonfiction book about being a teacher or if it should be a fiction book about being a teacher. I have many stories as a teacher could fit in either type of book but I would like to have a plot just in case someone wants to buy the movie rights one day. I do not have a larger than life story like Ron Clark, Jamie Escalante or Coach Boone. So, I am wondering if I could write a fiction book with elements from real life.

If there is anyone out there knows me and reads this blog. What style of book do you think I would, could, should write?