Ok, well first of all you need to set up a photobucket account, very very easy, and worth it. Go to www.photobucket.com
, and click on sign up now
, and then fill out the form and stuff, so you have an account. When thats all done, go back to the website and log in. when you log in, you can add photos, to do this from your comp click on browse and find the pic you want, then press SUBMIT. When you've done this if you scroll down your pic should there. Now underneaththe pic it should say URL, copy that bit and that is the URL bit you put on your profile here, for the avator.
I hope that makes sense