Go to "User CP" Then to "edit signature" or "edit avatar" and follow the directions. Make sure your picture is small. Hope this helps. There is another thread on sizing pictures, if that is the problem.
OlliesMom -- that's a great tip. I'm a new subscriber here and this is actually a test Post, and I'll be uploading a few pics. I use other software to resize pics but I tried that www.shrinkpictures.com site and it IS so easy -- I'm going to tell friends about it. So thanks!