First install that JDK + NetBeans bundle. Once NetBeans is installed, then in NetBeans go to Tools > Plugins. Go to the Settings tab, click on Add, and for the name make it something intuitive like "FRC Java". Use the following URL:
http://first.wpi.edu/FRC/java/netbea...te/updates.xml
Click OK, and then go to the Available Plugins tab. Check the five FRC plugins and press Install. Follow the prompts and after you restart NetBeans, voila.