find the pic.. upload it in imageshack.. use the link that it give you. with image tags.
for example in mine i have..
if you quote this you will see the image tags and the url.
you can just put image tags on the url of the pic you get from google or whatever.. but with something like imageshack you can make the image smaller to fit the screen properly.
OK..
find the picture you want to put in your profile.. whether it be on your PC already or one you have found on line..
Go HERE
if it is on your PC all ready click browse find it and click open..
if it is on from the net.. change the upload selection from file to URL..
paste the url of the picture you want.. resize it if you want to.. and click HOST IT.. you will get a few options.. copy one of them that is for what you want.
paste it in you profile and click submit modification at the bottom.. the picture should be uploaded in your profile then. keep doing this then for other pictures you want.