@boomerang,
There is one book about the Holocaust for if not very young people at least for young people - I think it is written very well.
I know that in at least one Swedish school it is used in history about Germany and the Holocaust:
The Boy in the Striped Pyjamas is a 2006 novel about living on the fringes of the Holocaust, from the point of view of a naive young boy, written by Irish novelist John Boyne.
Judith Kerr has written novels for children such as the autobiographical When Hitler Stole Pink Rabbit
There are many books written about this subject for young people and young adults.