Community Server Quickly from Packt Publishing, written by Anand Narayanaswamy, is designed to be a quick reference book for Community Server administrators.  It is a compilation of information from many sources, including Community Server's inline help and online docs. 

The book covers installation, general information about the individual applications within Community Server, and provides basic instructions/information for the control panel.  It holds back from going too in-depth or conceptual for a quick reference guide; keeping its descriptions short and to the point.

The book was written for Community Server 2.1, but most of the administrative help offered by the book still applies to Community Server 2007 (at least now... CS2007 will be released later this year and is subject to change).

Although this book's tag-line is "A concise and practical guide to installation, administration, and customization", it focuses mostly on administration.  The short chapter on customization definitely doesn't cover all (if most) ways to customize Community Server. From an strictly administrative standpoint, customization includes changing the site or blog theme or installing add-ons.  If you're looking for information on customization (writing add-ons, implementing theme changes, etc), you're probably better off waiting for (or also purchasing) Wyatt's book, Professional Community Server.

That said, this is definitely a book for administrators -- with its well-defined table of contents and index, it provides administrators quick access to brief descriptions of applications, configuration settings, and forms.  As a quick reference guide, Community Server Quickly lives up to its name, and belongs within arm's length of Community Server site administrators.

If you're getting started with Community Server, I'd suggest first reading the Community Server Overview on the Community Server site, and then skimming chapters 3 through 7 (covering the applications) and 9 through 11 (covering the administrative control panel) of Community Server Quickly.  I personally prefer the installation guide in the Community Server Docs to the one included in the book (chapter 2), but you may want to skim both and pick the one you prefer.