An interesting book genre mostly aimed at the older teen/young adult crowd. The stories told in these books usually reflect life in the city, with a character experiencing a recent hardship and getting over it. Most urban fiction novels tend to have a lot of erotica in them, as sex is a very common happening in them. Poking around in this section at the library can net you some really good finds. If you don't live in a big city, then these stories will pretty much give you a small (if exaggerated) taste of what living in a large city is.
A good urban fiction novel I've read told of a group of friends, most of them coming from dark backgrounds who manage to stick together throughout their childhood and into their adult years. It may sound silly here, but if you read the story you'll understand the whole thing.