This book explains the architecture of the 8051 microcontroller in a structured manner with plenty of good diagrams to clarify. There are many examples of how the 8051 may by interfaced to various common (and some more unusual) external devices. Each example discusses the relevant issues from both a hardware and a software viewpoint.
The author has taken time to ensure that all of the items necessary to get your first 8051 project up & running are included. For example, there is a circuit which shows how to make up simple power supply unit for an 8051 and details of how to reliably reset the device.
I especially liked the fact that the popular I2C and CAN busses were covered and that an example of a simple Real Time Op System was built up from first principles.
The appendix lists many contact points where a reader can find out more about the 8051, some frequently used software routines, a discussion of the popular simmstick format and other handy resources.
The accompanying CD ROM containes a demo copy of the popular UMPS assembler/debug environment as well as data sheets for many of the devices used in the book.
I'd recommend this book to anyone who has thought about using a microcontroller device, but hasn't had the necessary hardware and/or software know-how to get started. It would also be a good reference volume and source of new ideas for existing 8051 users.