For starters, the book is huge. Heavy. But this also means that the book has a lot of information in it.
The book starts with the "basic" operation, explaining how to... compile your kernel, how to administer users, filesystems, networks etc. As you can easily understand, this book is clearly not for newbies. It is for people who are already pretty familiar with Unix and Linux. If you are able to use Red Hat Linux, Debian, FreeBSD with some ease, even if you do not consider yourself a Unix wiz, then this book should be fully comprehensible. If you occasionally have trouble using even... Lycoris or Mandrake, you better check elsewhere.
The book will introduce you to the inner workings of Unix, how it really works, and most importantly, how you can administer it. You will learn how to partition and install both Red Hat and Solaris, learn to put up a small network, printing, file sharing, mail, apache, make backups and use the "hidden" features of X11. You will learn to write and use Cron scripts, databases, how to secure and detect hackers, and even a whole chapter how to interact with other administrators and users!
I am very satisfied by this book's depth, level and way of writting and explaining things. You will learn how things are working from the inside out.
There is only a single thing that I found dissapointing with the book: It is centralizing itself on Solaris and Red Hat, without talking about FreeBSD or BSD in detail. In my opinion, this is a huge left-out, as BSD is one of the two big Unix implementations surviving today and a lot of Unices are based on it like IRIX, QNX, OSX, BSDi, all the free BSDs and more. To be more precise, BSD had the right to be in this book, in the place of Linux (in case there was not enough space for all), as Linux is not officially a "Unix", while BSD is.
Other than that, I can't spot problems with this book. If you are into Solaris and/or Linux, this is definately the book you need to become that Unix wiz you were always dreaming about. Highly recommended. On the other hand, if you are mostly a BSD person, you might want to look at the "FreeBSD Unleashed" book.
Overall: 8.5 / 10
Buy "Unix Unleashed"
at Amazon.com for less