"Runaway", Wendelin Van Draanen (YA-realistic fiction)

"Runaway" is written in journal style and is about a 12 year old girl who is an orphan after her mother over-doses.  She is sent into various foster homes.  Her current home is where this journal begins.  Her foster parents are horrible and lock her into her "room" which is a cold laundry room with nothing more than a thin blanket and a bucket to use if she need to use the bathroom.  Her only way to get water to drink is to turn on the washing machine and drink that water.  After being sani-flushed and starved for the day because she objected to her creepy step-father's overtures, she runs away and manages to successfully get to Los Angeles.  This journal details her adventures for almost a year of living on the streets, including the perils and dangers of being 12 and living on your own with no means of support other than what you can steal or manipulate from people.  All in all, this is an excellent portrayal (if a little sanitized) of the dangers homeless people face as well as the problems with the social services system.