You need to work your way up tho. Do you know C/Objective-C?
If you know that much you can start with some books such as being an xcoder (i think its called) which walks you through the different types of apps and how development works.
Yea. It will take you a lot longer diving right into Xcode and getting going that way. Just read up on ObjectiveC and play with XCode building basic apps that run on a mac. From there, you can expand into the API for the iPhone and such.