You might want to give us more background on what you know about iOS, programming, CompSci, etc...
If you've never programmed in any language before, you might want to start with a book that covers 'intro to programming'
If you've programmed before and understand it, then I'd grab an 'intro to ios dev' type book.
There's a 'for dummies' book as well, good place to start.
You'll need to get a grasp of object oriented programming 'OOP' as that's what's used in iOS dev.
Best bet is to start with a intro book, give it several hours a day for about 1 month, then see where you stand.
YouTube has a bunch of videos that go thru the examples from books, that might help as well.
One important thing is that you can't get a good answer in a short period of time... You must be willing to hit it hard and regular for a few months.
I like the Big Nerd Ranch book, but that might be a good 2nd book for you, after a more basic 'for dummies' so that you'll get a better foundation.