well for the avvy go to user cp, then click edit options go to the bottom of the page and click the change avatar button and then pic one.
For the sig, find one u like then go to the General Disscussion forum and then to the Signature Request Thread(its always at the top of the page0 then ask someone to make the pic a sig with your user name or whatever u want on it. Then to put in the pic click on the Preview and spellcheck button under the Reply box, then go to browse and click the pic u want to put it in.