Mac OS X made its debut three years ago and is now on its third major revision, called Panther. It’s time for OS 9 holdouts to think seriously about junking the Classic operating system and making the switch.

So, how do you do it? David Pogue has hit the mark with his Missing Manual series. This Missing Manual is not as technical as O’Reilly’s companion volume, Mac OS X In a Nutshell, and that makes it perfect for people new to Apple’s UNIX-based operating system.

Pogue launches the book with first principles — everything from booting the machine to understanding the folder views and logging out again at the end of the session. There are also key chapters on making the switch between OS 9 and OS X, including running the Classic mode, which effectively emulates an old Mac within an OS X window.

Perhaps the most valuable part of the book is the appendices, especially the “Where’d it Go?” dictionaries for Mac and Windows. The idea is that if you can’t find something, and you’re used to Classic or Windows, you consult the dictionary and hopefully find an OS X equivalent.

Buy The Missing Manual for the Mac newbie in your life — or get it for yourself, and keep it stashed near the machine. Preferably out of sight, because we can’t have those Windows users asking why we Mac addicts have a manual next to our easy-to-use machines!