We have this and my boys love it. Even ds2, who would ordinarily walk over hot coals to get to chocolate (ds1 has sensory issues with chocolate - can't even stand the smell of it).
Each of the little books has either a christmas poem, carol or story in it, with lots of stories about christmas around the world.
We bought ours years ago when ds1 was about three and each book has a little green ribbon on the corner so you can hang them on the tree if you want to.
We read one of the little books as a bedtime story every night (in addition to reading The Night Before Christmas) and the boys take it in turns to then put the book on the mantelpiece. By christmas day we have 24 mini books with christmassy pictures all lined up across the top of the fireplace.
The only time it gets daft is on the night that the little book also has a slightly different version of the Night Before Christmas in it and ds1 insists we read both.

We are in trouble this year though, because dh was ill at the weekend and didn't get it down from the loft. Ds1 couldn't handle the thought that it was the first of December but we weren't reading the first book tonight. Oops!
I had to come across all scientific/mathematical and tell him it was a good thing, because there are 25 books but only 2 boys and 2 into 25 doesn't go. He then decided that we could consider tonight dd's book. Poor dd only gets one book, but at 22 months old, I don't think she'll be all that bothered - next year however will be a different story! Dh will now have to go up in the loft tomorrow evening after work, as I have run out of excuses. 