help section next time man
use paint, make the image size to fit within the bounds of an avatar.. u can find out how big that is when u try to upload an avatar.. hold on i'll do a little research for you
150x150 or 192 kb
then u can make it be whatever you want.. or you can google some images that are that size to find one already made
or a better idea would be to save somebodies avatar on here that they already have, right click on it and choose to edit.. then you can just erase and rebuild