I had used Flash once before, so I was pretty rusty coming into mobile application development. Having searched around for a while I decided on Flash Mobile Application Development For Dummies - though I must say I was worried that a Dummies title could be too dumbed-down. It wasn't, and I wasn't at all disappointed with what I got! For the price, I really get a lot more content than the other books cover and it's written in a far more readable manner than some of the other titles. I found the step-by-step code examples extremely easy to follow - I found others have a tendency to throw a huge chunk of code at you and expect you to decipher what it does! Attention to detail is high throughout, and found the online code resource helpful to see what the completed (and working) code looks like when you're finished.
One minor downside was the omission of details on how to use the camera on an Android or iOS phone in your mobile application. I imagine there simply wasn't enough room for another chapter! Even so, the book was a breeze to work through and I'm now using it as a reference as I build my second app.