Learn to create nice looking forum icon with this tutorial. Open a new file (
File>New), having
450x450 px and
72 dpi.
Using the
Ellipse Tool (U), try to draw next the primary layer of the icon to be.

The layer’s parameters:
Blending Options>Gradient Overlay
Gradient’s parameters:
Blending Options>Stroke

Make a copy of the new made layer and select the
Free Transform option to make the copy smaller a little, changing also the copy’s parameters: