Builder of Bowser steam! Railimages Site
OK. I'll assume you don't know how to post images to the site in general then. I'll aslo assume you want to use your own photos, and not a photo that you found on Google.
This code [*img]http://www.trainboard.com/railimages/data/500/Trains_038.jpg[/img*] produces this image when the * are taken out of the IMG tags. If I went into my "Edit Profile" page and pasted the above code into the "Signature" box, the pic would show up in my signature instead.