If its an image from your hard drive you will to host the picture on some web space.......
You can host the pic here
http://www.oldskoolanthemz.com/forum....php?do=upload
you may need to resize your image though in photoshop or similar as may be too big
Winner if youve already done it
once you have uploaded your picture in the link above......you can go into my images and you will see a link next to the image,
ie: [img]blahblahblah[/img]
copy this into your sig and hey presto