How big is your pocket?
The size of these books overwhelms the pockets on any piece of clothing I own, so the "pocket reference" description is misleading. Besides, I don’t know any programmer who carries reference manuals with them.
Each book assumes familiarity with the language covered, so they are not user guides or tutorials. They provide an overview of language syntax, along with directions for tackling various aspects of development, such as arrays.
Although Microsoft has been lauding the merits of the .NET platform for quite some time, the actual development environment is relatively new. Both the C# and VB.NET books cover version 1.0. Each provides an overview of language syntax, as well as offering details on specific elements such as arrays, classes, and variable types. Two good sections near the end of the books offer a list of the many classes in the .NET Framework and the usage of the .NET command-line tools. This is useful information, but it's readily available with more coverage in numerous other books and on the Internet.
Take it for a test drive
I placed the C# Language Pocket Reference on my desk during a recent project with the intention of using it when my brain failed. The online help provided by the Visual Studio .NET development environment is very good, so the real need came down to programming or logic problems as opposed to syntax. For that, this little book was useless. On the other hand, it did serve as a nice coaster.
Is your pocket big enough?
I enjoy most O’Reilly books, and I often find myself turning to C# in a Nutshell. Although O’Reilly had a nice idea with the pocket reference books, they seem like a stripped-down version of the reference and Nutshell books. Why waste $12.95 on the C# Language Pocket Reference when you can get more than 800 pages of real reference material in its Nutshell counterpart? You should save your money and buy a regular-size book.
I think the pocket reference concept is better suited for operating systems or applications, where commands and other reference material is not as verbose as that required by developers. In fact, I'm looking forward to getting a copy of Windows XP Pocket Reference.