If you have never read Nickel and Dimed by Barbara Ehrenreich, I highly recommend it. At this point, the book is probably a bit dated since the events written about took place around 2000. But in it Ms. Ehrenreich takes a series of low paying jobs and tries to make ends meet. If my recollection is correct, she actually starts her journey with enough money to find an apartment and she has a car (which she notes puts her well ahead of many of the folks in her travels).
Today, I read an nbc.com article that highlighted many of these issues. Yolanda Williams, the woman featured in this article, is trying to support an adult daughter, her disabled husband on less than $300 every two weeks. She spends 28 hours a week commuting by bus to work and to school. She also struggles to afford medication and treatment for her and her husband's diabetes treatment (which likely means more expensive treatment down the road).
It is distressing to hear about this woman, who is working so very hard, but doesn't seem to be making much progress.