Misaki-chan

You go to "Edit My Profile" then to "Change Signature". To add an image, it must be uploaded to some sort of website. I use photobucket.com for my regular photos, and if I'm using Rotasig (for the changing pic) I have to go to that and get my photos from photobucket. Then, you click the small icon next to the link, paste the URL, press enter, and you have your picture.