Hellobee Boards

I like "It's Okay To Be Different"! From Amazon: "[The author] cautiously calls attention to superficial distinctions. By picturing a smiling girl with a guide dog ("It's okay to need some help"), he comments on disability and he accounts for race by posing a multicolored zebra with a black-and-white one. An illustration of two women ("It's okay to have different Moms") and two men ("It's okay to have different Dads") handles diverse families sensitively this could cover either same-sex families or stepfamilies and also on the opposite page, a kangaroo with a dog in its pouch ("It's okay to be adopted"). He wisely doesn't zero in on specifics, which would force him to establish what's "normal." Instead, he focuses on acceptance and individuality and encourages readers to do the same."

There is also a book by the same author called The Family Book that focuses more on different types of families, but I haven't read that one.