I strongly recommend that you read Class: A Guide Through the American Status System by Paul Fussell. Although it was written in 1983, it is still the best description of the American class system that I have ever read. It's less than 200 pages, so you can read it within a day. It primarily deals with the social factors of class,which makes me think that it makes it a good choice for you because it will complement your existing knowledge of corporate culture.

http://www.amazon.com/Class-Through-American-Status-System/d...