Depends on how much you know

Anne Frank: Her Life and Legacy - Jemma J. Saunders

This isn't a bad book. If you have read the work of Prose or Muller about Anne Frank, however, this book doesn't really add anything to that. It is, however, a good starting point for someone who is interested in the history surrounding the diary. It can be read by both adults and children. In fact, if you have a child who has read the diary and wants to know more, this is a good (and affordable) place to start.