The current issue (6/15/04) of Wine Spectator magazine has a large section devoted to touring the Napa Valley.
It covers wineries, restaurants, shops, hotels. other sights to see, etc., etc. Two maps of the valley are also included. Granted, most of the "usual suspects" are covered and their picks do not exeactly break any new ground. However, as a basic guide to the area, it is a very nice package. Anyone thinking of visiting Napa Valley any time soon should pick up a copy.