I have recently finished reading the new Cisco Press book Enterprise Network Testing: Testing Throughout the Network Lifecycle to Maximize Availability and Performance by Andy Sholomon and Tom Kunath. Prior to reading this book I will admit that my only experience with network testing has been much more adhoc than the structure they present.
The first section of the book is devoted to learning about the methodologies, tools and types of network testing. This section discusses how to test networks and where in the lifecycle testing should take place. It also builds a case for why network testing is important and how to get funding and management support for testing. If you don't get anything else from this book, that chapter is probably the most important. Getting budgets for testing capital expenses (lab gear, space, testing tools) and operational expenses (labor, power, cooling) require showing the return on investment that can be had from preventing downtimes later.
The second section of the book looks at how testing of various types has helped real world businesses. These case studies give the reader a good idea of tangible benefits of network testing. Most of this section reads more like a business textbook than a technical guide which should help network engineers bridge the gap to the holders of the purse strings. As network engineers, we have to come out of our geek world and explain to non-geeks why what we do matters to them and to them business matters.
Finally in the last section the authors explore various network projects and the test plans used to verify their operation. For someone like me with no formal network testing training or experience, this section is an invaluable resource. The test plan examples are very thorough and will be a great reference for building your on test plans.
I highly recommend this book, although it may not be as sexy as say a book on the Nexus 7000 or FCoTR it provides useful skills for a network engineer to improve their network.