I have been here for a few weeks but I still haven't figured out how to get a picture underneath your name when you post on a forum. Could you help me please
Go to your "user cp" page. Then there should be an "edit profile picture" option on the left. (i'm not sure but i think some changes are limited when u're a new member though)
The custom avatar feature is for supporters. There are generic avatars you can choose from if you wish.
Like Aerienne says - the custom avatars are for supporters. But you don't gotta be a supporter to put your own pic in your signature line. (Boy it's complicated, this internet stuff. Can't we just go back to parchment, sealing wax, quill pens and carrier pigeons??)