Assuming a knowledge of 16-bit Windows programming, this book explains what is new and different about Windows NT and details what programmers need to know to exploit the feature or mechanism in their programs. The book contains chapters on NT's powerful memory-management system, issues relating to multitasking and a section explaining NT's otherwise opaque message-passing system with a powerful piece of code called "message crackers".
Much of the reference material from this book is available online at Microsoft's MSDN website.
The rest of the book covers how those pieces fit together. The book covers different kinds of files, the proper way to set up shared memory, the proper way to set up mapped memory, interprocess communication, threading, and other topics. Although the material is dated, for the most part that is only because the book doesn't discuss newer Windows features (such as slim locks).