Xcode 4.2.x seems to have different templates from the ones shown in this book. There is an equivalent template that helps you get past page 8, which I think is called "Single Page" or something like that. I'd check, except that I already went ahead and grabbed Xcode 4.1 so that I could follow along in the book more easily. As I discovered, there are more problems with having the latest Xcode once you get to Chapter 4.
If you'd like to join me on my quest to keep the book follow-alongable (new word I made up thanks to Head First products), you'll have to install the version of Xcode that the book uses. If you're running on Lion, the closest you can get is 4.1, but I suspect that the actual version would be 4.0.x, which only seems to work on Snow Leopard. In order to install an older version, you'll probably have to uninstall Xcode 4.2. Do that by typing the following into a terminal (which is under Utilities in your Applications folder):
sudo /Developer/Library/uninstall-devtools –mode=all
For more/better info on that, find the pdf that comes with xcode; mine's at /Developer/About Xcode.pdf.
Then you can download the older version from here:
Note that your download from here might just put an "Xcode Installer" app in your applications folder. Running that app installs the *actual* Xcode program. Afterwards, it can be trashed.
These books are definitely aimed at people (like me) who often have a hard time figuring things like this out, so it's such a shame that they so quickly become outdated. Good luck with your iOS development!