You have taken the photo of your piece of jewelry that has been well lighted and interestingly proped. Now you want to edit it and upload it to you listing. I have tried all kinds of editing programs....the winner is Piscasa..which is free see download http://picasa.google.com/ piscasa also including PicNic for adding words to the photos. It is easy to use (but everything does have learning curve).
I used these eHow instructions to get me started: