We added pages and got autographs for:
Tiana and Naveen
Phineas and Ferb
Rapunzel (She especially loved her page because she hadn't seen it before!

)
I also found pages for Handy Manny and Jake (Neverland Pirate) but my girls didn't want those pages.
I took the books to Staples. They cut off the binding, laminated the covers, added the extra pages, and spiral-bound the whole thing. I think it cost about $10 to do 2 books. I would really recommend getting it spiral-bound, even if you aren't adding pages, as it makes it MUCH easier for the character to hold and sign!
I can't find the pages I used right now, but they are saved on my desktop at home. If no one posts links, I'll try to do that when I am at home.