The subtitle for the book is 'Tips and tools for finding and using the world's information' which does neatly sum up its content. This is the third edition, so it is clearly popular, and has been updated to include information and hacks for Google maps, talk and desktop. As with any O'Reilly title, it is very clearly laid out, easy to read, with extremely good illustrations, small icons to indicate tips or notes of caution, plus an in-depth and thorough index. Each hack is clearly indicated by typography, an icon and the top corner of each page indicates the numbered hack.
What exactly is a 'Google hack'? The authors'description is 'quick and dirty solutions to programming problems or interesting techniques for getting a task done'. They then continue, focusing specifically on Google, by saying '... show you some tricks for making the best use of a search, to show off just what's possible when you automate your queries with a little programming know-how, and to shine a light into some of the overlooked corners of Google's offerings.' Consequently one may assume that this particular title is aimed at people with an interest in Google, who want to search more effectively and (this is the salient point) with the ability to use programming 'know-how' to create resources to do things with the search engine that might otherwise be difficult or even impossible.
The first chapter looks in detail at some of the basic ways in which you can use Google to do things of which you were unaware, and covers the use of the advanced search function, setting preferences and so on. It also provides the reader with some useful background knowledge on how Google gets its results. Some of the hacks are simple and very sensible, such as Hack 4: Check your spelling. Others will be of limited value to people outside the United States since they focus on functionality such as searching the Google Phonebook.
The authors primarily use Google, but they also point readers to external resources and Web sites when it sensible to do so, though such occasions are fairly few and far between. However, I do think that at times they are a little too biased towards Google, and there are times when they could, and should, be more critical. For example, they refer to the phonebook syntaxes as 'powerful and useful' and make the point that they are case-sensitive. There's no reason why they need to be case-sensitive, and most people would see this as a flaw with the system.
It's also worth making the point that much of the work is already dated. Now, we all know that any book that relates to anything to do with the Internet is going to be dated before it is published - we take that as a given and no one expects otherwise. However, with the dramatic increase in Web 2.0 resources, and the release by Google itself of utilities such as Search Builder, many of the hacks are, to all intents and purposes, rendered pointless. I was able to go through much of the book looking at different hacks and think of utilities that have been created in the last 6 months that will do the job almost as elegantly (to be fair to the authors, not always as elegantly as their suggestions), without requiring any knowledge of programming.
It would be unfair to dismiss all of the hacks in this way though - there are many that require no extensive knowledge; enthusiasm, patience and the confidence to fiddle around, backed up by the authors' detailed explanations, will pay dividends. Even if you feel unable to try the coded examples yourself, there is a wealth of information in the book which will give you a greater understanding of what Google is capable. If you bear in mind that it is quite likely that 6 months on from the publication date there is now an easier way of running a hack than is found in the book, simply use the book's suggestions as a starting point.
In conclusion therefore, expect to find this book interesting and informative, but perhaps not quite in the way that the authors originally intended.