Beginner: Custom Graphic

[Geebles]

I've been trying all day to make my "hello world" addon display a custom graphic on the screen. (since it is the basic bones of an addon that works) I've looked at so many things and haven't gotten anywhere.

I wonder if someone could show me some xml code to display a custom graphic on the screen?

I just want to take a png in photoshop, convert it to the right format, put it in the addon's folder, and see how to get that on the screen in the simplest way possible. I haven't been able to find a simple example anywhere that actually works to help me get started...