The 10th book did it for psychotherapist Richard Carlson. His Don't Sweat the Small Stuff, published by Hyperion in January, leads all the national charts and has 512,000 copies in print after 12 trips to press. It's a clear case of slow and steady wins the race -- the book's first printing was a mere 40,000 copies. An article in the local Contra Costa [Calif.] Times got picked up by the wire services, the author appeared on the Leeza show and did a bit of touring on the West Coast, plus some radio and local TV. Word of mouth kept this book going, and while an appearance on Oprah on May 27 didn't hurt, the book already was nearing the top of the charts. Hyperion has signed Carlson for an additional three books, one of which, Don't Worry, Make Money: Spiritual and Practical Ways to Create Abundance and More Fun in Your Life, is scheduled for October.