You are very fortunate to celebrate such an awesome birthday! I hope my grandfather is around 'till he's that age. I'd love to do something like this for him.
My suggestion would be to have the same design for all the pages. For example if the layout of your scrapbook page has the photos in the center horizontally then all the photos of the LO will be that way. Then you can embellish around them anyway you want. I do mini books this way and it helps me not to have to come up with ten or different designs for each page. Hope that helps and have fun!