Some, like me, tempted to buy this book by just reading the title, might be disappointed. The book is divided in three parts. The first part titled Running Eclipse, the second part, starting on page 185 about Extending Eclipse, and the third part, starting on page 623, filled with exercises. Together with a verbose style of writing this fills up the 854 pages.
If you consider the most important part of this book the second part (about extending Eclipse) the book's title should be interpreted as "The Developer's Guide to extend Eclipse". The book's title should definitely not be interpreted as "I am a Java developer, how to use the Eclipse IDE to write my Java code". The first part is not extensive enough to serve as more than an introduction to how to use Eclipse.
The second part of the book is slightly more useful, but does not go into the details that you need if you really want to extend Eclipse. If you want to extend Eclipse in a standard way, not wanting too much functionality, this will be clearly described in the second part. However if you want to step slightly besides basic functionality, you will probably have to struggle your way through the Eclipse API documentation and mailing lists. The third part offers you some basic exercises for all the chapters of part I, and one basic hello world type exercise covering the whole of part II. For the rest, each chapter in part II directs towards example code on the CD, which is interesting, but nothing much more than what can be downloaded from the Eclipse web site as well.
The book comes with a CD with Eclipse 2.0, handy given the size of the software, but not so handy if you consider that very soon the first release of 3.0 will come out. The CD also contains the exercises.
