We use the illustrated Disney encyclopedias which has a page for each major character. The characters sign wherever there is a blank spot and then I put the date and where we met them. My kids are little (almost 5 and 2) so sometimes characters we meet are their first exposure and they haven't seen the movie. Whenever we see a new movie they get very excited and ask if we "know" them and they hurry to flip through and check the book. There's also a brief blurb for each character which allows them to learn the gist. We do a new signature for each encounter (so, we have Minnie like 4 or 5 times with different dates) and if there isn't a page for the character they sign the inside cover. Every time we go to
Disneyland I get asked by at least five people where we bought it (
Amazon) and if it was expensive (it's not, around $15 each).