A picture book is a deceptively complex object: Ideally, it should be mind-expanding, psychologically astute, vividly illustrated, and—the most elusive criterion—fun. It must entertain the child without boring the grown-up to tears. And it should teach children to match sounds to meaning, pictures to objects, cause to effect, without feeling like homework. Finding picture books is easy; the market is glutted with them. The hard part is picking out just the right ones. What follows is an effort