Good luck with iOS. NSScreencast is not as useful as Railscast, but there are some pretty useful tips. For example, I thought this episode was really helpful starting off:
http://nsscreencast.com/episodes/63-from-scratch
I've also been hearing great things about Treehouse, which I plan to use when I tackle Android:
http://teamtreehouse.com/
Good luck with iOS. NSScreencast is not as useful as Railscast, but there are some pretty useful tips. For example, I thought this episode was really helpful starting off:
http://nsscreencast.com/episodes/63-from-scratch
I've also been hearing great things about Treehouse, which I plan to use when I tackle Android:
http://teamtreehouse.com/