I have always assumed that the O'Reilly Nutshell series was reserved for quick reference material - not much explanation, just the facts. The success of the series is exemplified by Unix In A Nutshell . This contains all of the commands, with all of the switches, that I am ever likely to need and it is one of the few books that I keep it beside my computer.
Internet In A Nutshell is not so successful. This is partly because the Nutshell concept seems ideally suited to command line computing. Quercia has tried to apply the same format, but it isn't needed for GUI software. In fact, I find listings of all the menu options for Netscape and Internet Explorer (and others) fairly tedious. The chapter listing 'landmark sites' is inevitably partial and dated.
The book covers a lot of ground; browser configuration and use, including plug-ins, the information 'out there', email, news, chat, and web authoring. Some parts have proved useful - for example, the search syntax for each of the major engines is described (there's that command line again). A complete listing of the 'currently available' HTML tags and attributes might also be useful when I get some time.
To be honest, I haven't found a great deal of use for this book and I don't keep it by my computer. However, I was already a fairly knowledgeable Web and email user when I received it and have not felt the need to broaden my Internet activity since then.