Newnham has one of the best college libraries in Cambridge. One of the reasons why it's so good is that in the early days of the College, women weren't allowed to use the University Library, so Newnham had to provide its own books.
It's a comprehensive collection, covering all subjects taught at Cambridge, and hundreds of books are bought in to update the collection every year. The library building is beautiful too. You have the choice of the beautiful old historic bit of the library, or the stunning new extention built in 2004.
The library stays open long hours (7am until 12.45am), and you can borrow most books for 4 weeks at a time, apart from some science ones, which are 3-day loan only.
For scientists, there is also one copy of each reference book, so you don't have to buy copies of all your key textbooks.
For more information on finding books and borrowing them, see the document below, or ask any library staff, who will be more then happy to help.
Email: librarian@newn.cam.ac.uk
Website: http://www.library.newn.cam.ac.uk/