TL;DR: Comprehensive recipes for data visualisation for beginners
This is not a book that can be read cover to cover. The book title doesn't mention it (and I don't understand why), but this is actually a recipe book.
The book is organized as a series of unrelated recipes, each one showing examples (source code with explanation) of how a particular visualisation can be acomplished using JavaScript and usually some ready-made visualisation library. I liked that the book does not focus on a single library, but instead the examples always use the best tool for the job. The list of visualisations is comprehensive, and covers everything from basic line charts to more complex map-based and dynamic visualisation. The book is obviously intended for beginners, but I liked how the author explains some of the more intricate parts of the presented codes. Besides examples showing how to visualise data using popular libraries, the book also covers some utility libraries, like underscore and backbone, that come handy when building visualisations; working with AJAX, and also shows how to build a more complex application with real data. The source code for all of the examples in the book and more is publicly available on github.
I usually have a problem with recipe-style books, because they fade out of relevance far too quickly, as the technology evolves and moves on, but this book packs more than just examples. Nevertheless, I'd only recommend the book if you are starting with data visualisation and need a good reference of what is possible and how.