For uploading an avatar:
1 - from the website
home page, click on the
profile tab, then choose
forum profile from the drop down menu.
2 - then click the
upload avatar button and browse the location of the image that you want from your device in the box to the right.
3 - for best results crop your image beforehand so that it is square! Note that the image displayed is only 65 x 65 pixels.
Hope that this helps