A New York Times article called For Young Latino Readers, an Image Is Missing, here, makes the point that few books for children feature Latino kids, even though the Latino percent of the public school population is large. I was shocked at many of the comments, which said, essentially, so what? People wrote in saying that they didn't need characters that reflected them to enjoy reading.
I think avid readers can enjoy almost any kind of literature, but my experience has been that children who are just coming to reading need to read about characters they can, in some way, identify with. Here is my comment on that article:
Better readers can enjoy a wide variety of books, but I found that when my students were just starting to enjoy reading, the books they most liked were ones that, in some way or another, illuminated their own lives. I could usually get black students reading with the Spenser books by Robert Parker because they loved reading about Hawk, the great black character. They also loved the Terry McMillan books.
But by high school it's late to get kids reading. We could do it earlier with high interest series books, with characters and settings, that better reflected the lives of our children.