It needs to be 75x75. If not, the system will resize it as it sees fit. You generally won't like those results. After you have loaded the photo to either the lighthousekeepers space or somewhere else where it can be linked and displayed, you then need to go to your profile. Select choose another avatar, which will open a window. Insert the link to where the image is, just as you would to display an image in a posting. It will display the image at the top left of the screen as I recall. Once the image you want displays, click on the choose this image button which will close that window and place the avatar in the main profile window. At the bottom of that page choose save and exit. You will probably have to completely exit from the forums site and re-enter before the avatar will display.