Maybe Colin Powell doesn't need to run for President -- now that he's Author-in-Chief. The sky-high expectations Random House had for his autobiography, My American Journey (which earned the general a reported $6.5 million war chest, er, advance), are being met: The book debuts at No. 1 on the list and is up to 1.25 million copies in print after three pressruns. ''It's the fastest-selling trade book we've ever had,'' says a Random House spokeswoman. And speaking of D.C. honchos, Newt Gingrich's tome dropped five spots this week, to No. 10, while his July novel, 1945, has yet to chart.

FICTION WEEKS ON LIST 1 THE HORSE WHISPERER Nicholas Evans, Delacorte, $23.95 2 2 MORNING, NOON & NIGHT Sidney Sheldon, Morrow, $24 2 3 ''L'' IS FOR LAWLESS Sue Grafton, Holt, $24 3 4 COMING HOME Rosamunde Pilcher, St. Martin's, $25.95 4 5 BEACH MUSIC Pat Conroy, Doubleday/Talese, $27.50 12 6 FROM POTTER'S FIELD Patricia Cornwell, Scribner, $24 7 7 A PLACE CALLED FREEDOM Ken Follett, Crown, $25 3 8 THE CELESTINE PROPHECY James Redfield, Warner, $17.95 82 9 COME TO GRIEF Dick Francis, Putnam, $23.95 1 10 MEMNOCH THE DEVIL Anne Rice, Knopf, $25 10

NONFICTION

1 MY AMERICAN JOURNEY Colin Powell with Joseph E. Persico, Random House, $25.95 1 2 MEN ARE FROM MARS, WOMEN ARE FROM VENUS John Gray, Ph.D., HarperCollins, $23 129 3 MY POINT...AND I DO HAVE ONE Ellen DeGeneres, Bantam, $19.95 4 4 THE SEVEN SPIRITUAL LAWS OF SUCCESS Deepak Chopra, New World Library, $14 31 5 A GOOD WALK SPOILED John Feinstein, Little, Brown, $23.95 15 6 NEW PASSAGES Gail Sheehy, Random House, $25 14 7 MIDNIGHT IN THE GARDEN OF GOOD AND EVIL John Berendt, Random House, $23 74 8 HOW TO ARGUE AND WIN EVERY TIME Gerry Spence, St. Martin's, $22.95 24 9 STOP AGING NOW! Jean Carper, HarperCollins, $24 8 10 TO RENEW AMERICA Newt Gingrich, HarperCollins, $24 12

MASS-MARKET PAPERBACKS

1 NOTHING LASTS FOREVER Sidney Sheldon, Warner, $6.99 6 2 THE BODY FARM Patricia Cornwell, Berkley, $6.99 9 3 THE ALIENIST Caleb Carr, Bantam, $6.99 15 4 THE HOT ZONE Richard Preston, Doubleday/Anchor, $6.99 11 5 SPENCERVILLE Nelson DeMille, Warner, $6.99 1 6 WINGS Danielle Steel, Dell, $6.99 2 7 INSOMNIA Stephen King, Signet, $7.50 7 8 COUPLEHOOD Paul Reiser, Bantam, $5.99 1 9 DON'T STAND TOO CLOSE TO A NAKED MAN Tim Allen, Hyperion, $5.99 5 10 STAR WARS: SHOWDOWN AT CENTERPOINT Roger MacBride Allen, Bantam, $5.99 2

SOURCE: PUBLISHERS WEEKLY