This tutorial will teach you how to make an unfilled circle in Photoshop.

1) Select the elliptical marquee tool

Right click on the rectangular marquee tool to find the hidden marquee menu.

Then click on the elliptical one.

2) Draw a circle

Tip: You can make draw a perfect circle by holding down shift as you draw.

3) Under the edit menu, choose 'stroke'

4) Click OK

Before you click OK, you can change the different options. 'Width' is the width of the circle, in pixels. 'Location' is where the circle will be created in relation to your selection. The default will be OK for now.