What are they? Rosés are usually made by siphoning off the juice of red grapes after a brief contact with the color-bearing grape skins. (Longer contact would turn the wine red.) Some rosés are produced by tincturing white wine with a little red wine, but the people who use this technique don't usually brag about it.
Where are they from? Most of the rosés I look for come from southern France--Provence, Tavel, Bandol, Languedoc, Roussillon. But Italy and Spain make some sensational dry rosés. So does California, though there it's a labor of love. Consumer confusion with treacly, sweet "blush" wines has discouraged many American producers.
What do you serve them with? Since dry rosés are as refreshing as chilled white wines, with the body and the spirited fruit character of light reds, they bridge a lot of gaps. In particular, young rosés are wonderful with smoky, salty, peppery flavors. They bring out the best in a dish of charcoal-grilled chicken, garlicky shrimp or peppery sausage, and there's no other wine you'd want with your ham sandwich.