One of the first tasks in any application I build is to setup a Dependency Injection container, provide a simple wrapper around the container itself, and make it available throughout the entire application. The reasoning is simple; all of the references are easy to contain, the application remains loosely coupled, and the dependencies are managed for you. The DI container composes the object and populates all of the dependencies automatically. To me, DI has always been a pattern undervalued in the .NET world, and so a book like this is great to make such an excellent design pattern known to the .NET world.
A really good book on Dependency Injection was published and is a good read for going from knowing nothing about Dependency Injection to becoming an expert in it. The book walks through the basics of DI: how to inject a reference and how to design your component to allow for dependency injection, object composition, and lifetime management. The book continues on to look at what’s good for DI, and what is an anti-pattern for DI as well.
The book follows up with how to setup DI using some of the most widely used Dependency Injection containers on the open source market. Each chapter illustrates how a user would setup the container, provide the references, and make use of the container within an application. It looks at the various configuration options each container has, and explains the nuances (each container does behave a little bit differently, even though conceptually they are very similar).
If you never looked into dependency injection, I would highly recommend that you do, and this book is a great way to start.