A slightly misleading title! If I were to name it, I might call it Nicholas: A Manhattan Christmas, New Year's, Twelfth Night, Valentine's Day, and Washington's Birthday Story. But I can see why they chose to be concise. The illustration you see on the cover also appears inside the book, just before the title page, and is the only color illustration. There are also few pictures of any kind in the book, which would really benefit from them.
Nicholas, our title character, arrives in New York City on a boat from Holland at the beginning of the book. He's wearing blocky little shoes, as you can see, and some homespun clothing. . . and is eight inches tall. This strange element of the story is never explained. After his arrival, he is met by a Brownie and brought to the Public Library, where a Christmas Party is being prepared. All of the characters from the storybooks are being invited. But before he settles in, Brownie takes him about the city to meet some friends and for some last-minute gift/decoration shopping. We meet a lot of jolly small folks of various occupations who all, inexplicably, know Nicholas (although he knows none of them). There is much feasting and gift-receiving for all.
The book is charming, at first, but gets old very, very fast. The plot of every section in the book goes something like this:
Random Character: "Oh, Nicholas, it's [special event/holiday]! Let's go [throw a party/feast] but before we do, we should go get [new character]. On the way we'll be sure to [stop at significant historical landmark/engage in event-appropriate activity]. It will be ever so jolly!"
Nicholas: "Oh, please, let's! That sounds like ever so much fun!"
And so it goes. This book could potentially be a fun read-aloud for some kid in New York who knows the sites involved, but one chapter at a time only. It becomes redundant fast (see above). The book has no plot to speak of, no antagonist, no conflict. Imagine High School Musical, but four hours long, with no Sharpay. And the book even admits, in a fashion that I'm sure the author thought very clever, that it has no ending. So what was the point?