Gallwey, W. Timothy.The Inner Game of Golf. Random House, 1998. Controversial view that too much thinking gets in the way and that relaxation and visualization are keys to success.
Pelz, Dave, with James A. Frank.Dave Pelz's Short Game Bible. Broadway, 1999. Explains how to analyze the weaknesses in your game and improve them systematically.
Peper, George, and Golf Magazine, eds.The 500 World's Greatest Golf Holes. Artisan, 2000. An enjoyable, richly illustrated tour of golf's most difficult holes.