Like others I spent a couple of long days finding the errors that are contained in the early chapters of this book. Maybe it's a reflection of a project delivered by a niche publisher without the oversight of a good editor, but it really does detract from the rest of the contents. In any case be warned that even the errata published on the web site, as well as other internet sources do not completely address the fundamental issues of installing and running LeJOS. It's too bad that what otherwise appears as an interesting work is so flawed.I purchased the book thinking that it might help me with accessing the lego nxt brick and Java programming. It is not a good book at all. Right from the start, the instructions were incorrect. The book directed me to put the lego nxt in firmware upload mode. I did. Then it instructed me to run a"lejosfirmd1" which doesn't even exist!!. I had to spend a lot of time just to recover the nxt from firmware mode(more time wasted!!) I blamed myself for not being able to connect the nxt brick. Started writing the first sample program in Eclipse, the book referred to classes(like the Pilot class) that do not exist!! This book is missing very essential instructions that could help the reader. You buy this book, you are on your own. The book does not have a section that may help look for the answers. It is inconsistent, poorly written, and frustrating.This book was published before it was ready. There are numerous inaccuracies, misleading statements, missing steps, incorrect file names, vague references, poorly written instructions and aggrivating projects that just plain don't work or suddenly leave you in the darkThis book has many good ideas and interesting topics BUT...NOT FOR THE NEW JAVA PROGRAMMEREven intermediate would be pushing it.Right from the beginning nothing works as the book describes:- LEJOS installation instructions are wildly incorrect- Developer environment installation and setup instructions are missing critical steps- Critical explanations and critical steps are missing throughout- Explanations will suddenly jump from explaining the basics to saying things like "Now download your favorite free chess program and hack it to control your chess playing robotic arm." -- Uh....okay..- Bluetooth set-up and operation does not work as described and steps are again - missing.- If you can't get bluetooth working, you can't do some of the projects and here again the technical level jumps from very basic to expert.- Programs can only be run ONCE then must be downloaded again to run them again.I'm sorely disappointed.The LEJOS project has a LOT of great potential and I will return to it at a future date but as it currently stands this book has left a very sour taste in my mouth.Publishing this book should have waited at least until book and product match up.It needed a lot more proof reading.Releasing the book in its current state only damages any LEJOS following that it could have inspired and damages the readers trust in the reputation of an author that is intelligent and very knowledgeable.If you are one of those Java guys, hands on, and a mechanical control lover, this is a book you don't want to miss.From programming point of view, some very useful topics are Bluetooth setup (both Window and Linux), Serial Communication setup, Vision detection, and Voice Control. You will be amazed of how you can realize those technologies into controlling an NXT.There are still many other interesting subjects from machanical/control point of view. This includes using GPS receiver(where you can learn NMEA Data format). It also shows you a NXT versioned Rocker-Bogie for rough terrain (I was really amaized how it works once I built a prototype). There is one special section to show you how to build a differencial gear using standard NXT parts. This really comes handy for a new Lego user who do not have an old differencial gear.This book also includes quite some attractive design like R2me2 (resemble R2D2), Moon Buggy, Beckhambot, Mapping Robot, and number 0.5 (resembles number 5). I do like their 'abstract' concept of the design.However, there are also negative part about this book.1. Some photo pictures is not very clear to follow. Either too small or too dark to see the details.2. Some mechanical design does not make it turn well (like Mapping Robot). But I guess this is due to lack of proper parts (such as differencial gear which was not included in the NXT package).I bought this book specifically to get some information on the NXT and some building ideas. The book has easily met my expectations in these areas. There are some great ideas for building robots and a bunch of good info about building techniques and the effective use of sensors. I don't plan on programming in Java (I prefer C), however the ideas and code in the book are easily transferable to any programming language. There are detailed building instructions and excellent examples that I haven't found in any other resource. For example, the standard building ideas are complemented with advanced material such as mapping, pathfinding, scanning, and speech. I'm glad I bought it.Although the book sounds otherwise, it is in fact a good start for advanced programmers. A lot of the code does not work right out of the box, but provides a good starting point for advanced programmers to build on. If you are a beginning java programmer, this book probably is not for you because it deals with concepts that are incomplete as described in the book, but an intermediate-to-advanced programmer can take these concepts and modify them as need be and quickly make easy projects more advanced. Overall, I think this is an excellent book but should be used by individuals with experience in programming in contemporary languages.well worth the money very good