This is a compact book, weighing in at around 200 pages. The size is appropriate for a book intended to help people with too little time. It is basically a pile of advice for those of us who are constantly fixing broken systems, answering user requests, attending meetings, and maybe sometimes actually working on our projects. Some of this advice you have probably figured out on your own, some you will find useful, and some you will disagree with. That's OK; take what you need and leave the rest.
The first chapter is in some ways the most valuable part of the book. It covers how to deal with interruptions, and lists some general principles of time management.
The book moves on to discuss various ways to maintain focus while working on tasks and projects, so that you actually get things done instead of responding to interruptions and destroying your concentration through multitasking. Then it recommends routines, so that you don't forget to do things and so that you don't need to worry about what to do. I have found the advice in these chapters to be useful.
The core of the book is "The Cycle" -- a system for managing your to-do items, appointments, calendar, and even long-term goals. I've been trying out parts of it, and have found that it has helped me avoid schedule conflicts, made me less likely to drop to-do items, and improved my follow-up. So far, it hasn't actually helped me get down to 40 work hours a week, although in all fairness, I'm not yet doing the full system.
The rest of the book discusses prioritization, email management (in particular, the principle of "touch once" -- which I have found to be an extremely effective way of dealing with email), time wasters, documentation (which is time management -- documentation helps you do things faster or delegate them to other people), and automation. Most of the advice here has been useful as well. My only complaint is that the discussion on shell scripting did not seem very useful -- if I didn't already know shell scripting, it would not have taught me much, or convinced me that I needed this skill for time management.
The book also contains advice on various topics that are somewhat tangential. Such topics include customer management, long-term goals, "managing your boss", stress management (which gets its own chapter), and personal time. While not directly related to the nominal purpose of the book, the points mostly seemed valid and useful.
On the whole, I'd say that this book is well worth its $25 asking price. I've known for a while that I have time management problems, so I once bought a different time management book, but never finished it; the other book seemed more oriented towards executives and managers. This book speaks to system administrators, and it does a good job. It's not a panacea -- to fix your time management problems, you not only need to know what the problems are, you also need to go to considerable effort to change your habits. But this book's advice has already helped me to improve my time management, and hopefully it will help you, too.