In our 6 day trip in February we saw 31 DIFFERENT characters, 3 or 4 couldn't sign autographs. We did 3 character meals, and ran into 6 at one time on Main Street, plus saw numerous others (Hollywood pictures backlot also has a few walking around). That trip had by far the most characters we've ever seen in one trip. Last week we didn't see nearly that many, but we weren't looking either since the kids decided after the previous trip they didn't need any more autographs!
What I did for the scrapbooks was cut out the autographs from the cheap autograph book I picked up for the kids, then decorated them for the pages in the book after the trip. That way I did't have to fit autographs to a pre-decorated book.