Head First iPhone and iPad Development (second edition) takes you, again, on a great journey across iPhone development related topics. What you get here is a gentle introduction into iOS programming.
Book covers most common issues you will definitely face during iPod development. It starts with introduction to XCode (iOS devoted IDE). What's worth mentioning here, it covers XCode version 4 (most recent one). Then it presents how to develop simple 'hello world' like application. This way, you can fell what coding for iPhone/iPad is in practice. Apart from that, you will be taught how to use multiple views (very common use case for iPhone applications), how to access data (both via plists and Core Data), how to use tab bars, and some of the iOS frameworks. In general, this is very gentle introduction to iOS related development. And it's written like any other Head Firsts series book. It uses simple language, simple examples and good analogies. This way, you don't have to pretend that you are an expert with the topic before you start to read it.
If you are new to iOS and Mac world you will definitely notice that Objective-C is something totally different than Java/C++/C#. Here, Dan provides you with the very basics of the Objective-C. However, these basics are tightly bound to UI related development. You won't get detailed syntax explanation here. If you want to get it, you will have to look somewhere else anyway. This is not that big disadvantage after all. In fact, most of the iOS development related books lack good explanation of Objective-C.
I have read Head First iPhone Development (first edition) some time ago. In fact, this had been one of the books I have learned to program iPhone from. I think it was a good choice at that time. I'd recommend it to all the people who are at the very beginning of the journey. If you know something about iPhone development already. It might be that this book will cover topics you already know. In that case, deciding for iOS 4 Programming Cookbook or Concurrent Programming in Mac OS X and iOS might be a better idea for you.