You have to have 100 posts before you can have an Avatar.Go to the control panel at the top of the page and edit your profile and if that doesn't work pm Laurel & Manu.I hope that this helps.
I don't know how to resize it should say on your control panel when you edit your profile but its best to pm Weird Harold he's the genius with Computers.BUT if your using a webtv pm laurel or Manu I hope that this helps