If you aren't already familiar with vagrant, it is a piece of software responsible for making a virtual machine be easily manageable and configurable from the command line. More than that, it can be used to make a developer's life much easier by hiding away all of the tedium of setting up a development environment per the product's specifications. This book is all about the whys and hows of running vagrant.
I was pleasantly surprised to find this book very useful and easy to read through. For me, I finished it in a couple evenings, and now use it primarily as a reference manual. It covers the important topics of networking and configuration in sufficient depth to be know what you are doing from a read-through.
I feel like what I learned most from this book, though, is that vagrant (fortunately!) is not all that complicated. You can get up and running quickly and basically be done with it. I do, however, now need a book on Chef for provisioning...
I'd recommend this book to anyone thinking about using vagrant for development. or anyone who has recently rolled out a deployment of it. If you've already been using vagrant for a while and don't need to extend it and are happy with your network configuration already, this book may not be a necessity, but it wouldn't hurt.
You can get this book from O'Reilly. I received this book for free through the O'Reilly blogger program, and chose it because we are using vagrant at my (!!!) new job.
Side note: Vagrant itself is amazing. If you are thinking about using it, I highly recommend giving it a try. It gives developers the ability to choose their own code editing tools while letting the product deal with all the necessary hosting headaches. It also makes it easy for new developers to get up and running.