I'd like to make sure that you know about a great new JavaFX resource that Sun's JavaFX Documentation Team has been working on. This resource, located on the JavaFX.com site, is called the JavaFX How-To's (although I like to call it the JavaFX How2 Compendium because it is a concise, yet comprehensive compilation of how to get things done in JavaFX).
For example, if you want to build a UI in JavaFX, you can refer to the how-to instructions such as Use layouts, and Work with controls, referred to in the screen shot above. Clicking on the Use layouts link takes you to an instructive guide, shown in the screen shot below, on how to layout a UI in JavaFX.
Enjoy the JavaFX How2 Compendium, and be sure to provide feedback so that the folks at Sun can continue to add how-to's that you want to see.
Regards, and enjoy!