hey not a stoopid question at all and tha is how we learn!

Go under "My Profile" when logged in. You can find that at the very top of the web page.

Open that - scroll down and look for AVATAR settings.
You can pick one provided or use your own.

If you use your own - you must have it posted on the web somehwere so you have a http address.

For a free picture hosting web - you coulduse Hunt101.com as they are free.

JW