Here's what you do, get a free membership at http://www.photobucket.com
and upload your pictures there. Open your picture at photobucket, right click on the picture and click properties. Copy the web address of the picture (don't use the webpage address in address bar, that's different) Then past a link to the picture. But put the IMG delimeters around it. I'm putting an asterisk in the web address, so you can see the text, otherwise it'd show you the picture, not the text:
If you put the "[img]"%20and%20"[/img]" around the link, the message board will just put the image as part of your post.