What i really liked about this tome was how broad it is. it covers a broad range of topics from software and hardware, to business practices and setting up a workflow.
i come from more of a technical background, so much of the hardware and software recommendations were old hat for me, (btw, make sure you pick up the newest revision of this so that it's suggestions are most relevent).
The business practices section was fantastic, as it detailed ways for you to work with clients and freelancers, dealing with employees, setting deadlines, and keeping track of timelines, project planning, and strengthening your workflow so that you can get your inspiration down when it strikes, rather than getting bogged down with all the details.
As a web designer the print, layout and fontography sections were of particular interest, as in this day, your project may likely end up in any number of media formats, even displayed on a number of devices.
While i wouldn't say this is the end all book, it has alot of great reference material, and it's a good jumping spot to follow up on deeper subject like XHTML, CSS.
In all, a very good investment.