When I started with ATL COM I had but little choice apart from this book. Since there are too many heads on each and every WROX book they spoil the broth. IT IS NOT FOR THE BEGINERS NEITHER FOR THE INTERMIDIATE. And now that I have got around 2 and 1/2 years of experience I still find it intimidating.

Best way to Start will be
1) Read Inside COM (Microsoft) Inside Out.
2) Graduate to Andrew Troelsen's Developer's Workshop to COM and ATL 3.0. The best that any one can get.
3) And Do read the MSDN.
4) For those who want then to jump into COM+ bandwagan read through Pradeep Tapadiya's 'COM+ Programming: A Practical Guide Using Visual C++ and ATL'

That will make you day. And hey don't forget to read the postings at develop.com and anything written by Don Box/Jefrey Richter.

Bottom Line - STAY AWAY FROM THIS BOOK

This is not a beginner's guide to ATL COM in any way, shape, or form. The first two chapters are dedicated to getting into the guts of COM and don't deal with ATL at all. This book fails to provide useful examples that a new ATL user can extrapolate from to fit their own similar problems, and it appears to assume several years of experience in C++. If you've never seen COM or ATL before, skip chapters 1 and 2 to start and go to chapter 3. Then after you've read 3,4, and 5, go back and read 1 and 2. I realize the info contained in them is important, but it is usually better to start out simple and get more complex, not the other way around.
On the other hand, if you are an advanced user, this is a pretty good reference for exactly what is going on under the hood with ATL.

This is an excellent book! Unlike other COM books where all they teach you is how to use the Wizard, this one makes you write a COM server from scratch, without the help of any wizards or relying on visual c++ to register the component for you. Then the author starts talking about wizards and how it and ATL helps you write components faster.

The writing is clear and concise. No BS'ing with the history of COM and how it will change your future 10 years from now. I would recommend buying Wrox's COM IDL & Interface design to go along with this book, as it will clearly explain the syntax of IDL and why they look that way.

Beginners may also want to read Dale Rogerson's Inside COM (Microsoft Press) before starting on this book, or you might have questions that go unanswered.