James Conway, a journalist and oenophile, is an informed and perceptive guide to the Napa Valley, the heart of the United States wine industry. He expertly combines history, personal anecdote, wine criticism and social commentary into a definitive portrait of a place, overflowing not only with cabernets and chardonnays, but also with genuine connoisseurs, scores of dilettantes, feuds, scandals and plenty of money.  (USW169, $16.95)