Hi:
There is a folder called "samples" under the folder that you installed JBuilder. If you want to view these samples, open JBuilder first, then, click on Open Project under File tab. Then, navigate to the "samples" folder, under which, there are all the sample applications. If you click on one of them, for example, the Chess example (you should have this one too), you should see a Chess.jpr file, click on this file, and the project will open. Then, just run the project. Or go to source to see sourcecode.
Hope this is what you want.