Bookshops
Hugendubel
One of the large German book stores also offering a wide variety of English books.
Bahnhofstraße 14, 30159 Hannover
Offener Bücherschrank - Open Bookshelf
At over 30 different locations throughout the city, you will find bookshelves which you are welcome to take books from, read them and then return them again. Of course you can also give own books that you no longer read.