No official rules yet. Just use your common sense. Don't put like ten images in a sig or anything huge like 800x600.
If someone's signature is waaayy too big or completely inappropriate, feel free to send a polite PM to the user asking to resize or change the signature. If that does not work, you can PM one of the Super Mods or me and we'll see if it needs to be changed.
Is there anyone here that can help me with my signature. I would like to put a picture of my car in it but all the pictures i have with me were taken at 5megapixel and are huge. Can anyone shrink them for me and possible make something cool. I am ok with computers, but when it comes to this kinda stuff i am terrible. I appreciate it. Thanks