[Nico]

This little guide provides some basic information on how to get started with iPhone programming.

The first thing you need is an Intel based Macintosh computer. Apple offers a free Software Development Kit (SDK), which does not work on PowerPC (PPC) Macs and Windows. If you only have a small budget, you can consider buying a Mac Mini, which is quite affordable, and perfectly fine for this.


Software Development Kit

You can download the SDK from developer.apple.com. It's completely free.
(UPDATE: The SDK is now available from the Mac App Store, it's called "Xcode" and costs $5.)



This SDK will add a new tab to Xcode (which is a program that comes with all Macs most Macs, or otherwise provided with the SDK). The SDK will also come with an Interface builder, and an iPhone simulator. These are the three primary programs you're going to use.

The programming language being used is called Objective-C. The SDK helps you to code, but obviously you're still going to have to learn it.


Standford



Standford offers a nice course which is freely available on iTunes. You can download a lot of videos and other material through iTunesU. I highly recommend you to check this!


Hello World



Here are some "Hello World" guides for the iPhone SDK:

iPhone SDK Hello World Tutorial - QJ.net
IPhone SDK HelloWorld - a knol by Usman Ismail


Protect your apps

Since iPhone app piracy is becoming more popular every day, you might as well consider protecting your code. The guys over at Ripdev have developed an additional protection layer which hasn't been broken yet by hackers. More info here: Ripdev: The iPhone Authority
(UPDATE: Project has been discontinued).



Getting your Apps on Apple's AppStore

In order to get your own apps on Apple's AppStore, you need to join the Developer Program. This has an annual price of $99, but it's well worth it if you have a few nice apps which you want to sell internationally. You can join the program here: iPhone Developer Program - Apple Developer Connection



After joining the program, you can submit your apps to Apple for review. This process can take several weeks. Once approved, you'll have your apps on the AppStore, and you're ready to make some money!


If you have any tips/comments/questions, feel free to post them here.