The main book collection is located on the 3rd floor of the library. A call number is equivalent to a book's address. Some book neighborhoods you might want to browse:
Q 300 - 390 = Cybernetics and Information Theory
QA 75.5 - QA 76.95 = Computer science and networks
QA 801 - 939 = Analytic mechanics
TK 452 - 454.4 = Electric apparatus and materials, circuits, and networks
TK 7885 - 7895 = Computer engineering and hardware
You can also use Central Search to find books by title.