While working in United States I found it is mandatory learning iPhone development. Also people around really appreciate and encourage you if you can make a nice iPhone app(I donno why, may be because they love Steve Jobs very much).
Searching for tutorial resource:
As I always do to learn anything I took help from google. I found most of the help topics are coming from apples developer site developer.apple.com. Unfortunately I don’t have much time to go through their steps. Or maybe I am so dumb understanding things in their way. So I start searching again then BINGO!! I found the ways it is most helpful is youtube channels.