Interracial Family Themes
I highly recommend author Cynthia Leitich Smith's site. It includes an article on the subject of children's and young adult books with interracial family themes, summaries, bibliographies, and family resources.
Gay and Lesbian Characters and Themes
An annotated list of children's books, from picture books to young adult books.
Interracial Family Themes in Picture Books
This annotated bibliography comes from children's author Cynthia Leitich Smith.