PreS Two sturdy board books that tell simple stories with universal themes. In Sleepytime. . . , Baby Mouse takes young listeners with her on her nightly bedtime ritual. Mommy and Daddy are both there to help, but they wisely allow Baby Mouse to do many things on her own. In Teddy Bear's Birthday, Teddy awakens his parents early, receives a wagon from his parents and has a party with four friends. The warm, full-color drawings are full of familiar details that children will love to point out , yet they never become cluttered or confusing. These books lack the sophisticated humor of Wells' ``Max'' books (Dial ) and are suitable for a younger audience. A solid choice in board books. Kathryn M. Weisman, Willowbrook School Library Media Center, Glenview, Ill.