I'm taking the online courses in their series as part of a continuing education effort that I've followed since beginning tennis as a child. I used to only read books and watch VHS and DVD training videos and now have added online tennis courses as a source for information.
The nice thing about this course is that it is broken down into six courses plus an on court training session. You can find a local on-court-course once you complete the online series. Another great thing about the courses are that you can stop and pick up again in a course at any time so if you are limited in your schedule you can complete these as your time is available. I started mine in mid July and hope to finish the last one in the series by the first week in August.
I rate these free USTA online courses as absolutely superb for the information, format, and ease of use. Check out their site and give the courses a try. http://coachyouthtennis.com
Teaching Credentials:
An added benefit for taking these classes is you will gain credentials for teaching tennis to children and this is a foundational requirement for certification in the youth tennis teaching curriculum of tennis teaching organizations. Additionally, you can use each of these 6 classes as continuing education credits toward the requirement to maintain your certification with the Professional Tennis Registry. It is a convenient way to help fulfill your needed hours if you are fully occupied with your teaching career and other activities.