Login, then click on the My Account button, then the Avatar tab.
Click on the Avatar Galleries until you find a graphic you like, then click on it.
That's it! The graphic you selected will now appear below your user name in all of your posts just like "Mr. Dot" does under my user name.
The only problem is that the Avatar Galleries are very limited. But feel free to use any graphic you like, just so it is 75 by 75 pixels or smaller, and a file size of 5,000 bytes (5 kb) or smaller. How do you know? Right click on Mr. Dot over to the left, then click on Properties. You'll see Size and Dimensions, and you can do this to check out the graphic you like. We keep the size of the images small so that the pages will load fast and not be too cluttered.
If you need help reducing the size of an image, just let us know!
To find your own image, try searching Google for "free avatars" and you'll find thousands. Or search Google Images.
Though you'll have more fun searching with Google yourself, here's an example of a free avatar site: