Occasionally, Denver bookman Cliff Janeway has one of those perfect days - he sells a couple of good books and he buys something even better - perhaps a tough-to-find Steinbeck in mint condition. Even the jacket is fine.<P>Working from his store on seedy Colfax Avenue, Janeway doesn't have enough of those days, but he's not complaining. Things are looking up because of his new partner and friend, lawyer Erin d'Angelo. So when Erin asks Janeway for a favor, it's hard to say no. She wants him to go over the mountain to the small town of Paradise where a former good friend, Laura Marshall, is in jail, accused of killing her husband. <P>What happened at the Marshalls' remote mountain home? Did Laura kill Bobby, or is she trying to protect her oldest son? And where were the three children when the shooting occurred? What did they see?<P>Rich with fascinating book lore and a tension-filled plot that's full of surprises, <I>The Sign of the Book</i> is the best yet from an acclaimed author who is himself first and always a "bookman."