Tutorials on 25 developer tools (both graphical and command-line, including
gcov) that ship with every copy of Mac OS X.
A powerful set of developer tools ships with every copy of Mac OS X, but this book doesn't stop with Xcode and Interface Builder. You'll learn how to profile your program with Shark, find memory leaks with MallocDebug, and write shaders with OpenGL Shader Builder. Building universal binaries that run on both PowerPC and Intel Macs is also discussed. There's something for every Mac OS X developer in Xcode Tools Sensei.
Xcode Tools Sensei was written for Xcode 2.1, and has been updated for Xcode 2.4. It comes in both print and electronic versions; the print version sells for $35(US), and the electronic version sells for $20. The electronic version is fully searchable, bookmarked, and hyperlinked so you can find the material you're looking for quickly. Free shipping is available for the print version.
Note: The author has stated that a revision for Xcode 3 (including material on Instuments and iPhone development) is in the works for the second half of 2008. (http://meandmarkpublishing.blogspot.com/2008/04/xcode-3-book-in-works.html)
Bonus: Also see the related articles on their site, available as free PDF downloads: