Those who like to do more with their Macs and aren't afraid to try things will appreciate this book. This is not aimed at absolute beginners although there may be some who are ready to jump in. The nice thing about this book is that there are topics covered that you don't always see in other books. For example, there is a chapter on connecting peripherals to your Mac and another chapter on Leopard as a web server. One chapter is devoted to "common Leopard maintenance."
As with most Leopard books, you get information about using the applications that come with Leopard, connecting to the internet, what the system preferences do and customizing your Mac.
Included are chapters on Darwin, Mac OS X Development and tools and cross-platform solutions. These advanced topics are not just a page or two, but chapters long which are a good portion of the book.
Some people may be scared off by all the advanced topics, but all the basics are covered too. It doesn't hurt to have both even if you aren't ready for all of it just now.