Richard,
I also read Savannah Brentnall's book "Object Orientation in Visual Foxpro", it is a really good object orienented concepts book with lots of good Foxpro specific examples.
If you are considering jumping in with both feet, but don't know where to start (I was in the same position last year), you should consider the Mere Mortals Framework. They have done a great job of building all base classes you need and their manual explains how to apply all of this for your specific application. The code is heavily commented and you can step through the sample project for some good examples.
You can find them in the Files section of UT or visit their web site at
www.oakleafsd.com. If you are really serious, they offer a five day training course on the framework.
Kind Regards,
Mat Kennedy
Decision Support Technology Inc.