Sonoma Valley, Calif., is a market that should appeal to retirees who are serious about their wines. The valley is home to three dozen wineries. But the market has more to offer than free wine tasting. Cooks should be attracted to Sonoma Valley as well because cheeses, French bread, sausage, vegetables, fruits, and nuts are all locally produced. What's more, the old adobe buildings and Spanish mission of the town plaza may delight those who would love to live in a historic setting. Sonoma Valley, a picturesque country between two mountain ranges, is located about 45 miles north of San Francisco.