The author does little more than recap information that is readily available in the SDK documentation, and has added hardly any thought about the practicalities of Azure development. (In fact, I could find NO evidence of such thought, but I've written "hardly any," in case I missed an iota.) For example, if you want to use an Azure Worker Role, you might create one from the template provided by the Azure SDK add-in to Microsoft Visual Studio. You will peruse the automatically-generated code and think to yourself, perhaps, "okay: what are the implications of the different alternatives for sleeping on the thread in the Run() method." You won't find that question or any others answered in Krishnan's book, though. What you will find is text that simply restates what you will read in the generated template. So save yourself $49.99 and just download the SDK and read the templates. Perhaps you want to use SQL Azure in your solution? The author devotes 9 pages to that subject. Here are a couple of things you might want to do if you actually want to use SQL Azure:
(1) Take a definition of an existing database and deploy that into Azure. There is nothing at all on how one might accomplish that ... not so much as a hand-wave in the direction of the Visual Studio Database Edition facilities that would allow you to generate a complete definition of your database for deployment to SQL Azure.
(2) Connect to a SQL Azure database from an Azure Web or Worker role. Krishnan has a code snippet showing how to accomplish that (which one could have found in the Azure SDK documentation easily enough) but not a word about how one might not HARD CODE the connection parameters, but instead get them from configuration, and, in that case, how best to secure the configuration information.
Questions like these would arise for anyone who is actually trying to write anything more than a "Hello, World" application, and who develops software professionally. There are no answers to any of those sorts of questions here. I believe I have read all of the books on Azure published to date, and among those, Tejaswi Redkar's "Windows Azure Platform," is by far the best.