The easiest way is to use the e(fx)clipse plugin, which you can download from http://marketplace.eclipse.org/content/efxclipse#.UPlblqGLx4U
Then create projects with File -> New -> Other -> JavaFX -> JavaFX Project and you should be set.
Failing that you can just add the jfxrt.jar file as a library to a regular project (Project -> Properties -> Java Build Path -> Libraries -> Add external jar, and navigate to /Library/Java/JavaVirtualMachines/jdk1.7.0_11.jdk/Contents/Home/jre/lib/jfxrt.jar).
Myself, I'd probably follow what is provided in this blog:
but the fact that Maven is involved might be a step too far depending on your current experience level.