White Rook,
Go to "My Account" then Change Password/Settings." Look for this: URL for Signature Image: (optional)
Please include http:// at the start. Images should be formatted at 75 pixels in height. Images will be FORCED to this height. File size should not exceed 30kb (30,000 bytes). Please do not link to images hosted on this site.
Then, after you have made your SIG image with some type of photo editing software and saved it somewhere like the Armorama gallery on MSN, past the URL in the box. The image size should be 320 by 75 pixels.
Then, everytime you post the picture you created will be below your posts.
Something like this...
Hope this helps. If you have more questions post them here or PM me.
Shaun