Once at the site, find the album title and the corresponding artwork. If you are at a website like Amazon or CD Universe, click on the album cover art and continue to click on the cover art until it doesn't return a larger version.
If you're a Windows user, right-click on the artwork and select "properties." If you use a Mac, right click (or control-click) on the artwork to open it in a new window.
Download the JPG file to your hard drive.
Once downloaded, upload the artwork by clicking the "Upload album cover art" link on the article submission form.
We highly recommend Google to find photos.
Be sure to contact the photographer, ask for permission, and credit accordingly.