I don't know any particularly good articles/books on this subject, but Morgan Spurlock had a documentary tv series called "30 days" where he spends 30 days doing things like living on welfare, working for a minimum wage job, living in prison, etc. It's a fascinating show, and while he's the first to admit that even this level of exposure is not equivalent to what people in those situations actually feel (largely because he has a safety net, and his is only a temporary condition), it still dramatically shifts your view of what life really is like for people in very different circumstances.

http://en.wikipedia.org/wiki/30_Days_%28TV_series%29