PAPERBACK BESTSELLERS.(BOOKS)

FICTION DIVINE SECRETS OF THE YA-YA SISTERHOOD, by Rebecca Wells. (Harper Perennial, $13.50.) Three generations of Southern women. 325 RISING TIDES, by Nora Roberts. (Jove, $7.50.) Returning to his home on the Maryland shore, a man finds a new love and hope for the future. 13 THE BEST LAID PLANS, by Sidney Sheldon. (Warner, $7.99.) The relationship between a power-hungry governor and a beautiful woman determined to wreak revenge. 23 ORPHANS: BUTTERFLY and CRYSTAL, by V.C. Andrews. (Pocket, $3.99.) A troubled orphan is adopted by a couple who hope she will become a ballerina. 412 UNNATURAL EXPOSURE, by Patricia Cornwell. (Berkley, $7.99.) Dr. Kay Scarpetta contends with a …