What programming language should a beginner use for developing apps for mac and I phone etc

Objective-C 2.0. Install xCode for practice.

If you want to develop apps natively, you'll have to go with Objective-C (language), Xcode (IDE), and the Cocoa Touch libraries. Objective-C is a super-set of C. So, if you've no background in C, start there. In fact, here are three books I recommend:

Dave Mark, Learn C on the Mac:

http://www.amazon.com/Learn-C-Mac-Dave-Mark/dp/1430218096

Aaron Hillegass, Objective-C Programming: The Big Nerd Ranch Guide:

http://www.bignerdranch.com/book/objective-c_programming_the_big_nerd_ranch_guid e

Joe Conway & Aaron Hillegass, iOS Programming: The Big Nerd Ranch Guide (3rd Edition):

http://www.bignerdranch.com/book/ios_programming_the_big_nerd_ranch_guide_rd_edi tion_

Dave Mark's book covers C, and you probably don't need all of it. Once it gets to really elaborate storage issues (for which you'll end up using Core Data on iOS), you can skim. On the up side, you have some programming experience, which will make learning C easier. On the downside, it's in VB, which isn't as similar to C as most other languages are. But, it's a start.

Hillegass covers some basic C in his book on Objective C as well. So you might can start with that. The final book only touches on Objective-C lightly and is really about using the iOS frameworks to do real work. It's entirely project based and will get to you building things and testing them and really creating iOS apps.