Even before I started working on the JavaFX project, there were a handful of very brave outside individuals who have dedicated tremendous energy to tracking our bleeding edge. I've had the pleasure of working with two of them in particular, Stephen Chin and Jim Weaver, and I'd like to call attention to their JavaFX book (hot off the press):

Pro JavaFX Platform: Script, Desktop and Mobile RIA with Java Technology

This book is everything we'd like our documentation to be: organized, thorough, practical, and easy to read. In fact, I'll be using it as a general reference myself for the areas of JavaFX for which I don't personally slave over.

As early adopters, the authors of this book have been happy to share their experiences with us in ways that have strengthened the apis and platform and I am personally grateful for their feedback -- even when Stephen tells me I got something wrong (like LayoutInfo's width/height should have been called prefWidth/prefHeight :-).