An appealing pocket-sized book explores a concept that every loving parent enjoys teaching. In succinct, deftly phrased quatrains, McLerran sums up the uses and messages of hugs (``A hug can mean `Hello there!'/A hug can mean `Good-bye'''), some touchy situations (``At times you want to hug them back./At times you'd rather not''; ``A kitten sometimes likes a hug,/But just a very light one''). Morgan's cheery, skillfully limned toddlers and their caregivers are a heartwarming, multicultural bunch. A companion book, Kisses (what else?), gets into metaphorical kissing as well as the regular kind: ``The weather gives you kisses, too...Sun on your cheek,/snow on your tongue....'' A disarming valentine of a book, for a small friend or a larger one. (Picture book. 1-5)