Signature Help

Well, I've been looking for help in every forum... I've got some questions... How do I make my sig. picture bigger? Some guys have huge pictures. And mine only allows me to put in a 500 x 100 (VERY SMALL) picture. And, how do I put a video in my signature? AND... when I take SS, how do I post them? MEGA THX FOR HELP...

well, with videos, you can only use youtube. Just put a link in your sig and the forum makes it like, you click it and they see it