Easy Peasy
Go to User Settings at top of this page, click on Edit Options, scroll down to Avatar & select, click the browse button. Assuming you have a picture already saved somewhere on your PC that you want to use, select that file name by double clicking it so it appears in the browse box & click on 'submit modifications'. If you get a message saying your pic is too big, use your picture editing software to reduce the size to 75x75 pixels - you will probably have to use a 'custom' size rather than reduce by 50%/25% etc. If you want to use a picture from the net , first select the picture by clicking& dragging a frame around it, right click & select 'save as' and then when it's saved go through the steps i've already mentioned! It took me an hour the first time i tried it as i'm not a 'geek' but i can set up a new avatar from the net now in 30 secs, so persevere!
L8rs, Guppy