The books in Coe Library are organized by subject--yes, there is method to the madness! Sometimes you can find a great source simply by reading titles on the shelves in an area relevant to your topic. However, because communication is interdisciplinary, you'll probably find relevant books in other sections too.
HM1206 - HM1236 -- media and society. propaganda. persuasion. public opinion. HM is found on Level 2.
P87 - 96 -- communication. mass media. P - PN are found on Level 3.
PN1990 - 1992.92 -- broadcasting.
PN4699 - 5650 -- journalism. the periodical press, etc.