Go to your user control panel and then on the bottom left you'll see a link for attachments. Click on that and then find the image you want to use. Right click on the filename and click on copy link location. Then go to the post you want the image in and type in {img} except with [ and ] in place of the { and } hit CTRL-V on your keyboard to paste the image location and then type {/img} except with [ and ] in place of the { and } . Hit post reply and it'll be there.