The official documents are always the best documents to learn something. You will get the most authoritative explanation in it. This situation is also true to iPhone developer. The iPhone develop official site is here: http://developer.apple.com/iphone/. It’s better to view in a Safari browser.
Though you have find the official documents, it’s better to learn some iPhone App background before you start to view these documents. iPhone Human Interface Guidelines is a good article to learn this. Certainly, a iPhone or iPod touch will be a best tool for you to learn develop iPhone App. iPhone Development Guide is a good develop process introduction. iPhone Application Programming Guide should be your first document to learn developing.
Mac OS X
You should have a Mac OS if you are developing iPhone apps with Objective C. So, the better idea is to have a Mac. If your budget can’t afford a Mac, you can refer to this post: 5 Methods to Make iPhone Apps on Windows PC or this post: How to Create iPhone Apps With Flash CS5. However, I recommend you to have a Mac if you have enough money.
The official develop language is Object C other than c or c++ or java. Though it is similar to c/c++, there are still some difference between them. cocoa is a framework written by object-c. If object-c is c++, the cocoa should be MFC.
You can learn object-c on a Windows PC. Find idea here: http://www.gnustep.org/. However, Windows can not support object-c 2.0. www.itgeeg.com
Xcode is a Mac ide. It’s like the visual studio of Windows. It is a great product help users to code best Apple Apps.
Third Party database
The official iPhone SDK is a powerful database. But sometimes you will find its shortage. Find some third-party database is a good idea than develop from nothing by yourself. You can see tutorials on this website: http://www.stackoverflow.com
Back to Official Website
Most time we get a problem is caused by ignorance on official documents. The official website offers rich documents. Each document will tell your who need to read it. Don’t ignore these documents. You can find direction after read these documents. read the fucking manual is also suit for iPhone App developers.
Though we just need API reference in our code, the reference in a document is also important. Read guide, overview, discuss to learn clearly about the problem.