If you're not using AppleScript, you'll learn how. If you're sharing a Mac with someone else, you'll learn how to set up multiple email accounts and Internet configurations. There's a full chapter on PowerBooks -- from increasing battery performance to ejecting stubborn floppies. Good, solid info on QuickTime, printing, and of course, the de rigeur chapter on coexisting with Windows users.
Responsible for managing Macs on a network, running a Mac OS server or providing Internet services to Mac users? You'll find this book even more valuable. There's great coverage of new tools like the System Profiler, step by step techniques for setting up a Mac web server, and tons of essential security information that's often left out of warm-and-fuzzy Macbooks. There's also an exceptionally good CD-ROM, with Mac shareware and freeware that's often hard to find -- especially stuff for those responsible for networks or Internet services.