PAGE ONE OF THE PLANETARY TUTORIAL.
SECOND PAGE WILL COVER RING PLACEMENT ON THE PLANET.
I have not created the 2nd page yet but I will when I begin a second planetary ring digital painting again.
This tutorial isn't exactly "Great" but it should give you a general idea of what to do.
EDIT: HIT ALT+CLICK WITH THE MARQUEE TOOL IF YOU ARE HAVING TROUBLE GETTING A GOOD CIRCLE.
For my new comp have been having that problem, if you too have same issue hit Alt+click to get the marquee circle centered around where you are clicking!