There are a large number of libraries in Karlsruhe. Not only will you find plenty of books here to deepen your knowledge of the lecture content or to research a term paper, they are also popular places to study for students who appreciate the quiet atmosphere in which they can concentrate on their work. 
Please note that it's the quiet atmosphere that makes these places so valuable. If you want to meet as a group to work on projects, there are group rooms or other open learning spaces that are more suitable for it.

There are four libraries in Karlsruhe that will be relevant for you:

DHBW Karlsruhe has a small specialized library with a few study places, PCs for research and a printer.

With more than 200 study places and a large selection of books on all possible topics, the BLB in the centre of Karlsruhe, offers a good opportunity both to find the right book and to study there. Some books cannot be borrowed. There is a reading room where you can read the books. The focus of the BLB is on non-fiction and specialized literature. You can search for books here.

As a DHBW Karlsruhe student, you can have your student ID card activated as a library card.

In the Stadtbibliothek im Neuen Ständehaus, you will find a large selection, not only of non-fiction books, but also novels, crime novels, comics and much more. There is also an international section with books in various languages.
Workstations and PCs are also available in this library for research.
There is a reading café on the ground floor, where you can sit comfortably and read newspapers or magazines.

Here you can search for books or simply go and browse through them in person.

The library of the Karlsruhe Institute of Technology is the first port of call if you are looking for books on technical topics. There is a very large selection on three floors. The library offers a lot of seating, more than most other libraries in Karlsruhe, but it's the hardest place to find a seat, as many of Karlsruhe's students study there. The special thing about that library is that as a student, you can go there around the clock. While the other libraries are closed on Sundays, public holidays or at night, you can always go there and get in with your student card. Especially in the late evening or at night, the library is very empty and quiet and the perfect place to study for night owls.
To be able to use your student card, you must first open a library account.

With the help of the seat finder you can check how many seats are still available in the different libraries.