Hiya, you need an online photo account for the pictures/images, which you copy the link to in your signature or avatar space.
Or you go to somewhere like tickerfactory.com and make your own ticker for your angel, which you then copy and paste the link to here in your siggy space.
You can go to your signature/avatar etc by clicking on User Control Panel at the top left, then Profile, and it will give you the option to 'edit avatar' or whatever you want to do. (Avatar is the little piccy at the left under our names, signature is the big space under your whole message)
Hope that makes sense?