If you need some help in this area, try The Brown Bookshelf is the place for you. As I posted during Hispanic Heritage Month, it's good to have a list of books that showcase diversity for your students. The Brown Bookshelf provides just that, complete with author interviews, book reviews and tons of information about black authors and illustrators. If you're looking for books about black characters or by black authors and illustrators, chances are likely that this blog can help you in your quest. The blog also is making February their 28 Days Later initiative , which they describe as "a month-long showcase of the best in Picture Books, Middle Grade and Young Adult novels written and illustrated by African Americans."
I'm always impressed when I visit classes and schools that have a broad representation of authors and characters in their books: male and female, different cultures and ethnicities, socio-economic backgrounds, etc. It's part of helping students become better readers and recognizing the value in people's differences. The Brown Bookshelf is just one resource that helps teachers in that regard.