[ninty]

You mean a picture?

Go into your profile and in the part that says signature type:

[img]http://www.whereeverimageis.com[/img]

You have to find the pic somewhere and put the address inside the img things. If you make your own sig, you will have to upload it to the net and then link it over.

There should be a "BBCode" link on the page that tells you how to do everything like that. Take a look at that if your confused.

Hope that helps.