Everyone should read this book, of course, even people who use Windows computers. (My accountant made me say that iDVD is, of course, a Mac-only program.)
All kidding aside, this book is for anyone and everyone who uses iDVD. More specifically, it's for people who want to know more about the program and about making DVDs than they'll find in the iDVD Help system. But most of all, it's for iDVD users who want to learn how to burn better DVDs.
Since iDVD is still a relatively new application, I make very few assumptions in this book, but I do assume that you know the basics of using your Mac, such as how to turn it on, launch a program, insert a disc, click, double-click, use menus, create folders, and so on.