Bhavani has written an excellent blog
on how to profile a J2EE application running in GlassFish using the new Netbeans profiler.
The tutorial starts with a list of things you need to get and follows that up with a brief explanation of the application in question. The tutorial then guides you through the steps of configuring then running the test environment. He includes a nice screenshot of the expected output from the test.
Bhavani concludes by mentioning other features of the Netbeans profiler as well as a link
to more detailed documentation.