http://www.webtennis.com/players/serve-course/
Tennis Serve: follow that link to discover the 5 simple secrets to unlocking your ability to naturally pronate to get better power, spin, and control on both your 1st & 2nd serves.
2009 USA National 60s singles champion Brent Abel of WebTennis shows you how.
http://www.webtennis.com/players/serve-course/