Upload the pic you want to use into your personal gallery on zonalos. once uploaded, just right click on your picture and "Copy Image Location". after that you will want to go to Profile --> Signature --> Then paste your link into the box after clicking on the IMAGE tab.
Be sure to go to Profile --> Preferences --> then click yes on the "Always attach my signature" or else it will not show up. there were a few of us that had that problem after getting our sigs uploaded.
Hope that helps.