I suggest consulting the great internet god, Google.


Also, wrong forum.
Play the man, Master Ridley; we shall this day light such a candle, by God's grace, in England, as I trust shall never be put out.
Newbie forum.

But you search on Google for an image you like, use an image editing program (MSPaint will do) to make it the approriate size, save it to your computer, and on the avatar section of your CP, upload it as your av.

I'll help...

Find an image
Resize the image using some program/whatever
save it
go to edit avatar in your user cp
upload it