Log On
Select Profile (top centre of page along with other options)
Scroll down to the bottom of your profile until you come to
Avatar control panel
Displays a small graphic image below your details in posts. Only one image can be displayed at a time, its width can be no greater than 100 pixels, the height no greater than 100 pixels, and the file size no more than 6 KB. Current Image
Use
Upload Avatar from your machine: to browse the hard disk of your PC (c:\) and select the image you wish to be displayed as your AVATAR beside your name when you post. You'll see mine to the left.
Of course life is made much easier by finding an image first and having it on your PC. See the previous posting where I put a link to 1000s of possible Avatars.
Good luck!