First of all, it is set during WWII, so you have to know it can't be the cheeriest story. It involves war, and death, and deprivation.
Secondly, it's narrated by Death. So, again, doesn't point to the warm fuzzies.
But it is a lovely book. A story about a young German girl in an unusual home in a small town in Germany. Her family takes in and befriends a Jewish man during the war, but eventually it becomes too risky, for him and for them. The girl cannot read, but her foster father patiently and painstakingly teaches her until she becomes a lover of words and a stealer of books.
It's not the typical Holocaust story or just a book lovers' story, but it is beautifully written and touching.