Morris (Weddings, p. 1114, etc.) and her longtime collaborator, Heyman, join for three books that look at basic human relationships in the new The World's Family series. The Baby Book shows large, full-color photographs of babies all over the world eating, sleeping, crawling, playing, being bathed and carried, accompanied by the simplest text. A key at the end tells a little more about each baby, often identifying the child's ethnic group or nation. The Daddy Book (ISBN 0-382-24695-0) and The Mommy Book (24692-6) are parallel titles of equal appeal; the three work together as a fine set. But skip the fourth entry in the series, The Animal Book (24701-9). The photographs (not by Heyman but from various collections) are rather arbitrary, and Morris has written a text in doggerel, marred by forced rhymes, poor grammar, and misinformation. (Picture books/nonfiction. 2-6)