Berlin is full of libraries, from the magnificent Staatsbibliothek on Unter den Linden to smaller special interest libraries, such as the Gay Archive and Library attached to the Schwules Museum. Access to the public library system is free but to take out books requires a membership. There is a nominal fee for membership, but bring your passport and Anmeldung (proof of residence) to get your card. The public library system is in extremely good shape. It is used by major universities, so it has an enormous variety of academic texts and some other resources, such as language learning and entertainment.