If you are not yet familiar with stackoverflow.com, you should try it immediately. It's the greatest Q&A site about programming (and other stuff on its network's domains).

There are over 20,000 questions answered about JavaFX already. And, if you don't find your specific question, you can always ask a new one. JavaFX tags are monitored by several experienced users, and questions are usually answered within a few hours.

The main StackOverflow address for JavaFX is https://stackoverflow.com/tags/javafx.