It started out as a child's board book. I pick these up in charity shops when I see them, they make great mini books or just chipboard covers - 3 pairs from one book!
I learned the hard way not to just leave the book intact and try to decorate it... my pages tend to be on the 'fat' side and the board book usually ends up not closing at all. I now remove the pages from the spine and trim them up and punch them with the BIA.
Because the books are made for very young children they tend to have a very shiny coating on them so that sticky finger marks can be wiped off... this makes adhering paper to them a tad more difficult so I always give the pages a good sand down so that adhesive keys to them.
I also made her a little box to keep the book in. I thought if she collected stuff from her holiday, postcards, pictures etc that she has somewhere to keep them all ready for when she starts to fill the book up.