It's a bunch of interviews with people about their jobs. A cross-section of the American worker. The point was to get people talking about what they do for a living, but that got people talking about all sorts of things, some personal things that they probably don't share too often. Sometimes it's just about life in general.
In full disclosure, I'm not sure if I read all the interviews in the book. There's no need to read them in order, which I didn't, and I ran out of renewals from the library. Here were some of the more memorable jobs:
McDonald's crew member, CEO, supermodel, Kinkos co-worker, drug dealer, escort, highway flagger, temp.
Flip through the table of contents on Amazon. It's worth picking up a copy if only for a couple chapters.