This booked is packed with well organized examples, but, the authors assume you already know a bit about about UNIX or Linux. However, the examples are so well done that even a complete newb to UNIX can figure it out (albeit with more effort and more slowly than someone who is already familiar with UNIX or Linux--difficult, but, not impossible). Great for a support tech, like me, who's been supporting Windows for years, but, has been suddenly (and joyfully) tossed some Macs to support.
I'm giving it 4 stars as the publisher, Wiley Publishing Inc., decided to go cheap and print the book on paper thats usually used for mass market paperbacks. For a reference book I think that's a bit unacceptable--especially for the price.