problems with html

hey guys i want to put a picture in my signature but i have read the page that is the link to easy HTML from here. it still is something i dont really understand. i like simple answers. http://wh0rd.org/cookie-monster-abusing-cookie-dough.png there is the link out in space and i have it saved on my computer at work here. how do i enter it into that box that reads forum signature?

sweet thanks guys!!! i laughed at my own signature...