Downloading and Installing NetBeans IDE
3. Read the NetBeans Documentation
At a minimum, you SHOULD READ the "IDE Basics, Getting Started, Java Application", which is accessible via NetBeans's "HELP" menu ⇒ Help Contents. This will save you many agonizing hours trying to figure out how to do somethings later.
The "Help" ⇒ "Online Doc and Support" (@ http://netbeans.org/kb/index.html) contains many articles and tutorial on using NetBeans.
The NetBeans "Start Page" also provides many useful links to get you started.