Instead of making a thread in the art section, please look at the many tutorials in the Tutorials Section of the forums.
http://lastmoon.org/forum/tutorials/how-to-upload-images-and-more-to-the-forums!/EDIT: I forgot to add, you need to get the direct link to the image, which you can identify because it will end with a .gif , .png , or .jpg , depending on what the image is. I've fixed it for you this time.
