MTY, if you want to upload a personal pic you probably have to take it from facebook or bebo or some social network site,alternatively you can upload your pics to tinypic.com(have never done it myself so i am not sure how it works).
Now,This is where the fun starts

your pic must not be more than 80x80 pixels(dont ask me why)
Right click the image,click View image info and then copy the image location.
now in your profile click the URL to your avatar button,then paste the image location in the box below.
Then click submit
hope that works,im not the I.T guy by the way,Murph is just to lazy to type that much.
just had a quick look at the profile menu,there seems to be a browse button you now use to upload from your hard drive,must be new.