A project I am currently working on required me to find an efficient way to displaying a "heat map" of data throughout the United States. While one approach would be to simply create static images, the map also needed to be updated based on different data parameters. We also wanted to be able to generate tooltips and zoom in and out of the map. These requirements led me to the D3 library and a nice book entitled, Getting Started with D3 by Mike Dewar that helped get me up and running.
This is a short book, designed to get you up and running quickly, using a real world scenario of the New York Metropolitan Transit Authority in order to provide working examples of code. There is a short introduction about the D3 library itself and then you are brought straight in to a basic example of data binding to an unordered list. From there the book increases complexity, going to scatter maps, dynamic interaction with the data, and even timed updates.
This is a "learn by doing" book that doesn't go into much theory or structure. For some people this may be an issue (I wound up using some online sources to cover the mapping specific needs I had in conjunction to this book), but if you need something to get up and running immediately, then this is an invaluable resource. I will be going back to this book often in the future, as it outlined how many powerful features are available through the library and I will have many projects in the future where this will come in handy.
You can get this book through O’Reilly Books at http://shop.oreilly.com/product/0636920025429.do.