Once you have aquired your image in the appropriate size.
Click User CP.
Then click signiture on the left hand side.
Use whatever image hospting website you wish to host the image.
Insert the link for the image inside the space, if the website you are using only offers a direct link than please make sure to place the link in between [img] [/img] to make it appear appropriately.
Please remeber to keep your images sizing with in this websites set guide lines.
"Its only a little bit on fire"