This is a collection of twelve short stories, one for each month of the year. It was pieced together through a sort of Q&A on Twitter, where Neil Gaiman would ask a question for each month, and he wrote a story based on his favorite answer.
I don't need to hype up how awesome the entire thing is - the idea, the stories, the illustrations. I mean, it's Neil Gaiman.
However, seeing as how my entire review should probably be more than me saying, "SQUEEEEEEEEE!!!", I'll try to get my thoughts together.
My favorites of the bunch were the stories for January and November, although each of the twelve stories were awesome in their own way. The story with the book igloo (July, I think?), had fun imagery - a world painted in books and pages. And the story about the anonymous Mother's Day card (May?) was very fun to read.
Each story has an illustration that goes along with it, and the illustrations are gorgeous. Each of them feel like a perfect summation of the month - both the story, and the weather and colors you'd associate with that month.
Again, January and November's stories are my favorite among the illustrations.
And, to top it all off, the story is free online, as a pdf download, and as an audiobook.