It is a really easy countdown. I just wrapped up all of our Christmas Books and labeled them with numbers 1 through 24. I luckily had enough Christmas Books on hand thanks to a Scholastic order that I placed before I even decided on this countdown:). The vast majority of the books I wrapped were ones we had from years past.
(Gingerbread Pirates is Charm's new favorite book. He has requested that we make cookies that look like a crew of pirates for Christmas. We will be having a very pirate-y Christmas this year!)
We are really enjoying this countdown because it is so simple. I also really like that it doesn't involve sweet treats (which abound this season without a daily 'countdown' treat in addition) or a daily cheapo gift that I'll have to pick up 1000 times this month:). Books are good. Books that you already own are even better!! Lucky and Charm get really excited to open a book every night, and they really enjoy our special reading time too.
As an aside, if you are looking for Christmas books to add to your collection, you might want to take a look at this post at Modern Parents Messy Kids. We actually don't own any of these book suggestions, so I put several on hold at our local library...and maybe next year St. Nick will bring one or two of the books:)!