When beginning a new NetBeans Platform application... there is always one crucial question that you should ask yourself in the design/architecture phase of the project. I.e., before you put your hands on the keyboard, you should have TMINPQ answered. The entire direction of the application will depend completely on the answer to that single question.
What is that question? In under 15 minutes from now, that question will be very clear, if you watch this brand new YouTube movie:

You're happily coding along and suddenly think to yourself: "Hmmm. I wonder where the 'pos' variable in my class is used throughout my application?" So you right-click your "pos" variable and choose "Find Usages":

Now, as always, you see the dialog below where you can set the scope of the search and whether comments should be included:

A recurring question in the NetBeans Platform world is: "How am I supposed to change the desktop shortcut icon and icons of the executables in the installation directory of a NetBeans Platform application installed on Windows via an installer created by the NetBeans Platform installer infrastructure?"
Let's use the Paint Application, one of the samples in the New Project wizard, as an example. Right-click the project node and choose "Package as | Installers". Now go outside NetBeans IDE and find the generated installer, double-click it, and complete the wizard.

I came across David Geary's article HTML5 2D game development: Implementing Sprite behaviors yesterday. The article ends with a download ZIP file.