First you must find a host for your sig,
Boomspeed is a good place fo that. Then go into your user cp, and go to edit profile. Then go to the signature box and put [*img]yourhostnamehere[*/img] Just remove the stars. For example, mine is [*img]http://members.lycos.co.uk/jaajoe/hpbimg/metroidsig.jpg[*/img] without the stars of course. Then check one of your earlier posts, and if you did it correctly, your signature will be thier.