I find some photos that I like (you seem to like Peter Pan, so I would use that) and edit them into a collage on Picnik. After I add my pictures, I put some Disney quotes (i.e. The Second Star to the Right, You can Fly!, etc.) and Voila!
I agree with Drew, Picnik is a really good- FREE- website to use to edit photos! You could always use photobucket too.
As for finding Disney photos, just google them! Or iconator has some really good avatars (it won't let me post the link on the DIS. but just go to iconator. com and search for "Disney" or "Peter Pan" or whatever you want, and make sure you change "icons" to "avatars")