To find books on Computer Science you can browse the library shelves in these call number ranges:
QA 75.5 - 76.95 Electronic computers, Computer Science, Computer Software
TK 5101 - 6702 Telecommunications
TK 7800 - 8360 Electronics
TK 785 - 7895 Computer Engineering, Computer Hardware
The library is catalogued according to the Library of Congress and from here you can see a break down of all call number ranges.