Here's a very interesting graphic on How Class Works in America. Since we are a new and improved society, we like to think that we are classless, that all are equal. But we know that's not true, and lately class struggles and definitions have been all over the media.
Paul Fussell wrote a great, if slightly out of date, book on the subject a while back that is at least as dead-on as the Times chart. More recently there was The Rise of the Creative Class. And you can never do wrong with good old Edith Wharton.
As for me, I did pretty well on the intereactive Times chart, but only because they weren't taking into account how often you talk about your sex life in a public forum. Clearly that would have knocked me down several points.