I found this 100 yard sight-in target on the internet, downloaded it, and brought it up in Photoshop. All I did was add the text "100 yard target. 4 clicks = 1 inch". I changed the black round bullseye to red and added yellow into the corners for contrast.

When you click on this, download it for yourself, etc... you have to choose that "fit to page" printer setting, or whatever you have... Then it will accurately print out on 8½ x 11 piece of paper with 1" grid lines.