Check out the site's FAQ, John. It says:
Can I post Images?
Images can indeed be shown in your posts. However, there is no facility at present for uploading images directly to this board. Therefore you must link to an image stored on a publicly accessible web server, e.g. http://www.some-unknown-place.net/my-picture.gif. You cannot link to pictures stored on your own PC (unless it is a publicly accessible server) nor to images stored behind authentication mechanisms such as Hotmail or Yahoo mailboxes, password-protected sites, etc. To display the image use either the BBCode tag or appropriate HTML (if allowed).
One free image storage site that may work is Photobucket.com. I'd like to see your pictures.