I made a homemade autograph book for my two kids before we went to Disney World this past April, I decorated the covers but left the inside pages blank because you never know which characters you are going to run into and I didn't want to create a lot of bad feelings if we didn't get a chance to see so-and-so. I held the pages together with loose-leaf rings (decorated with ribbons) so that after we got back I could rearrange the pages into a more logical order. I had the characters sign only the right side, and I added a photo of my child with the character on the facing page. We didn't fill up the autograph book with autographs so I used the extra pages like a photo album of some favorite photos from our trip. My kids really like their books.
Disney World Autograph book #1 By Kathy Heilmann
Disney World Autograph book #2 By Kathy Heilmann
Also, when I had taken apart their books to rearrange the autographs I also scanned the best autograph from each character (they signed both books but inevitably one was neater than the other) and then printed the scans out at reduced size on cardstock. Then I cut these mini-autographs out and am using them on my scrapbook pages (still a work in progress).