1. While logged in, click on the Profile link near the top of the page
2. Click on the "Avatar" link on the upper-right side of the screen
3. After where is says "Upload Avatar from your machine", click on the browse button
4. Find the picture you want, click on it, then click open
5. Click on the save button at the bottom of the screen
your custom Avatar should now be displayed on the side of all of your posts!