Try searching on Google for images that you want. Click on the image, then click "View Image" at the top or something like that. In the address bar will be the address to the image. Type this exact address into the "online avatar" bar when selecting Avatar Options.
You can also use pictures that you have on your computer. I took a picture of my tama with my digital camera, and made that my avatar. Just make sure that the picture isnt TOO big, otherwise it wont work. You can always make it smaller, then use it as an avatar.
