Write your first iPod app: article
Being me, I had to do a little extra just to stress myself. I made HelloWorld a “universal” app–which means it should work on the iPhone (and iPod Touch) as well as the iPad. I used two nibs. Build and Run always seems to bring up the iPad view in the simulator–have to figure out how to get it to run the iPhone.
It occurs to me that one of the reasons Apple is so successful is due to the very large amount of developer documentation available. IBM and Microsoft are/were pretty good at that too. It’s a monumental task to keep documentation up to date. So much of what is in the Apple OS dates back to NeXT which starting in 1985. ( Wikipedia article).