Is this book still useful if you have OS X 10.5? I am only in chapter 2 and already the page 22 Developer Applications section refers to hard drive applications that I don't seem to have, such as Xcode and Interface Builder. Do I need to download them from the Apple Developers site?

If you have your OS X install DVD, you can install it from there. Otherwise, google Xcode 3.0 and find your way to Apple's developer web site. You can download the installer from there as well. The following website will walk you through the install from DVD option. Once you've done this, you'll have a /Developer folder on your Macintosh HD root directory... with all the Xcode tools and goodies in there.... as described in the book....

http://gemma.apple.com/documentation...cs/Basics.html

The book is still useful for a lot of the concepts but I would highly recommend you move on to Leopard because the tools have changed quite a bit. You can, as Troy151 has already stated, download the tool set for XCode 3.0 but the newest set of tools required Leopard. Here is the quote from the ADC downloads page.

Interface Builder is where most of the differences are. The newer version handles classes and instances, as well as the control palette, much differently. As I stated earlier, the main programming fundamentals and objective-c syntax can be learned perfectly well if you have Leopard. Have a great day.