Examine the characters to see if different races, ethnicities, genders, religions and abilities are illustrated. Not every book can include every culture, of course, but constant omission of a group implies that the group does not matter to society.
Look for stereotypes in the text and illustrations -- such as Native American characters portrayed as primitive or savage. In addition, check that minority characters are portrayed as individuals with their own personalities and characteristics, not simply as token minority characters.
Consider the ways in which the book portrays beauty. Determine whether the book emphasizes physical appearances of female characters. Check whether the beautiful girls are depicted as blonde, white and thin -- and whether the positive characters are more attractive than the negative characters.
Examine the book's conflict and resolution, as well as the relationships between the characters. Consider which characters are the leaders, and check whether the male characters are typically in charge. Determine whether minority characters play an active role, or are subservient or in the background.