I can not agree with recommending ARC to anyone at this time; in this case there is a ton of existing code out there which is incompatible with it. If you are an experienced obj-c developer who's tired of writing boilerplate and uses the static analyzer with LLVM - then go for it.

Learning to clean up after yourself is a life skill worth having. And besides, there's always the -fobjc-arc flag for classes which use it.

EDIT: Every project seems to include: Reachability SBJson ASIHttp

And also commonly occurring: OpenUDID ZipKit NSLogger InAppSettingsKit (there are others) Cocos2d/3d

You can disable ARC for some or all part of your program, so lib compatibility is not a problem.

Thanks for the heads-up on ARC.

Not averse to managing memory :-)

If you need to include those files in your project, you can just turn ARC off for them while leaving it on for the rest.

I suggest you to do a search after iOS 5 on Amazon and check the comments before buying a book. I'd stay away from any of the Appress books on Objective-C, iOS, etc ... low quality of information and a lot of typos.

Personally I don't have a preferred source and I tend to use Apple's documentation or tutorials from websites like:

http://www.raywenderlich.com/

iOS is a moving target so it is difficult to find a good book on this.