For avatar, you can just copy and paste the URL at the Edit Avatar section at Your Control Panel.
http://i797.photobucket.com/albums/yy253/Chaos_Master999/Dustin2.jpg
http://i797.photobucket.com/albums/yy253/Chaos_Master999/Dustin1.jpg
As for your sig, copy the code and paste it at Edit Signature section.