This 40 chapter 1500 page Administrator's Companion is aptly named as you will refer to it extensively over time. Out of the 5 different versions of Windows Server 2003, the book covers the Standard Edition and the Enterprise Edition extensively. The Datacenter Edition is very similar to the Enterprise Edition so this book could suffice. The Web Edition is significantly different and is NOT covered in this book.
The Small Business Server is kind of the fifth and unofficial version of Windows Server 2003 and I am not very familiar with this Edition yet. This last version is not explicitly covered in the book but it is possible that it is actually only a slight variation of one of the other four versions. I am not familiar enough with this last version to make any other comments.
Windows Server 2003 is not as much of a jump from Windows 2000 as Windows 2000 was from Windows NT. This is good news for those familiar with Windows 2000 and hence can start using this book as a desk reference immediately. If you are new to the Windows Server family, then it is important to read through the first few chapters and take your time absorbing basic networking and operating system concepts before delving deeper into the book. Regardless of your level, you will find that this book is written in a very simple yet detailed fashion. Of course, the advanced users will find it the most useful.
The book is divided into six parts plus the Appendices. The different parts are - Preparing for Installation, Installation and Configuration, Network Administration, Support Services and Features, Internet Servers and Services, and Tuning, Maintenance & Repair.
I plan to take the MCSE for Windows Server 2003 (Microsoft Certified Systems Engineer) sometime next year and I am finding that this is a valuable addition to my preparation book list. There are plenty of books out there that help you prepare for this set of exams but you will still need a good reference on Windows Server 2003 in order to pull all the knowledge together.
Overall, I am happy with the money I spent on this book and I am using it quite often as I design and set up my own small business corporate network. All the way from setting up the Exchange Server for e-mail to Windows XP Professional clients for the different people using the network. The network devices are so easily found by Windows Server 2003 even if the device is attached to one of the client machines and not directly on the network.
One final note - even though this book is an excellent desk reference, I am finding that you still have to supplement this book with others depending on your goals. For example - if you are preparing for any of the MCSA/MCSE exams, you will need exam preparation guides. If you are installing specific software like Visual Studio.NET, you may run into some issues that are not covered in this desk reference. The bottom line is that when you get to the Advanced User stage, you will probably need a whole host of other books to supplement your knowledge. And some people find this book to be too heavy to carry around so it may be worthwhile to find a pocket reference type of book for that purpose. I hope you find this review helpful and good luck!