The list author says: "My list 'General Guides to iPhone Application Development' explains how to get started in iPhone application development, and lists books which cover the development process as a whole. Inevitably, they leave things out. The books on this list cover features in more depth, cover the more complicated or obscure features, or cover related topics, such as marketing.
Amazon and the publishers' web sites have free excerpts from many of these books. The publishers often have computer-readable software examples, errata, and other information.
Books are listed in publication order, oldest first. Normally, a newer edition is preferable to an older one, so I may list only the newest edition in print, and the next edition, if one is pending.
Note: Publication dates shown are those listed by Amazon, when I first add the item to the list. I update them from my best sources, shortly before publication.
Apple's recent hardware/software release schedule (which drives book contents and release dates):
October, 2008: Apple began allowing publication of iPhone OS-specific material for all released versions of the iPhone OS. (iPhone OS 2.1 and the first two generations of iPhone and iPod touch hardware had already been released.)
June, 2009: iPhone OS 3.0 (with many new features) & 3rd gen iPhone (compass, video camera, faster processor)
September, 2009: iPhone OS 3.1 & 3rd gen iPod touch (faster processor, larger memory); 2nd gen 8 GB model kept
April, 2010: 1st iPad (fast iPod touch, 5x the pixels, compass, & microphone; and optional GPS and cellular data), with iPhone OS 3.2
June, 2010: iOS 4.0 (formerly called iPhone OS 4.0), with 'multitasking' (multiple apps running), and iPhone 4 (much-higher-res screen, 2 cameras, 3-axis gyro)
"2nd edition, published October 21, 2008, by O'Reilly.
Written by one of the leaders in the hacking community which grew up around the "jailbroken" iPhone and iPod touch before Apple released the iPhone SDK. Explains the procedures used by that community. Applications developed by these methods will not generally be acceptable for distribution by Apple."
"Published January 9, 2009, by Addison-Wesley Professional.
One of the examples from the first edition has been reworked as an iPhone OS example. The other OS-specific information is for Mac OS X. The information which is strictly about the language applies to both."
Apparently gives the examples you don't get in Apple's Human Interface Guidelines. Excerpts are available at Amazon, not at publisher's web site. Apparently the code examples are not available for download.
While the publisher's description mentions the iPhone, I have seen no evidence that any of the material in this book is specific to Cocoa Touch (the iPhone OS variant of the Cocoa framework used in Mac OS X).
The (rather skimpy) complete source code examples are available for download from the publisher."
"Kindle edition published September 4, 2009. Paperback published around October 1, 2009, by Wiley.
It is not clear from the description that Cocoa Touch (the frameworks for iPhone OS) is covered in this book, although the author also wrote a well-regarded 'Dummies' book on iPhone application development."
Sequel to the authors' 'Beginning' book (item # 8 on my 'General Guides to iPhone Application Development' list). Covers extensively Core Data (new in iPhone OS 3.0 and iPhone SDK 3.0) and networking (skipped in the previous book), and (less extensively) some other topics. Does not cover cut and paste, or in-app purchases."