I can understand where learning C and DirectX would have it's advantages to beginning programmers, however I would personally recommend something a little more platform-independent. Congratulations on having the motivation to learn a programming language though, it seems that fewer and fewer people have the patience to do that... I hope that the book suits you well.
As I'm sure you're well aware, you do not become an expert overnight, so please take your time and actually learn from your experiences. Take your time, and be sure that you do not limit yourself to that book. Try to program a few simple programs that are not examples in the book, yet within your capabilities as you learn. You will be surprised at how much this helps improve your skills. It forces you to think on your own, as opposed to simply copying code from a book into the compiler.
And never feel confined to that book alone. There are many great tutorials online that you can read as you are reading your book. There are many approaches to programming even the simplest programs, and I am sure that you will find these tutorials to help you think about these different approaches.
I wish you the best of luck in learning C/DirectX.