I think it's personal preference about binding the pages or keeping them loose. They both have pros/cons.
If you bind the pages into a booklet, it is much easier to carry around (although it may be heavier). You can easily flip through the pages and organize them however you want. Pages don't get lost or crumpled when inside a booklet. Characters can easily sign the page because the booklet provides support. However, when you are done with your trip, you may have lots of pages blank in between. I've seen people make one big booklet, and others have made a several small booklets (one for each park, and one for character meals).
If you have loose pages, you can organize the signed cards in a photo album or bind them later. You will have to bring a clipboard or something to place the cards on for the characters to sign. You'll also have a stack of loose cards that can get messy. You have more flexibility with your cards to scan them and use in your photo albums.
My personal preference is to have a stack of loose cards. I have a small decorated clipboard that we attach the cards to for the characters to sign. I have a 4x6 photo album that has 4 photos per page that I put them in after they get signed. We look at the photo album a lot, just like our trip photos. You'll probably want to think through your strategy before you start printing them all out. It's lots of work, but they are so wonderful and make good memories.
Have fun!!!