iPhone App Programming - Documents

Property List Programming Guide for Cocoa :
http://developer.apple.com/documentation/Cocoa/Conceptual/PropertyLists/

Archives and Serializations Programming Guide for Cocoa
http://developer.apple.com/documentation/Cocoa/Conceptual/Archiving/

SQLite in 5 Minutes Or Less: http://www.sqlite.org/quickstart.html
Intro to the SQLite C Interface: http://www.sqlite.org/cintro.html

Brent Simmons, “libxml2 + xmlTextReader on Macs: http://inessential.com/?comments=1&postid=3489
Big Nerd Ranch, “Parsing XML in Cocoa”: http://weblog.bignerdranch.com/?p=48

JSON Parser/Generator for Objective-C: http://code.google.com/p/json-framework/
Introducing JSON: http://www.json.org/

Memory Usage Performance Guidelines:
https://developer.apple.com/iphone/library/documentation/Performance/Conceptual/ManagingMemory/

Threading Programming Guide: https://developer.apple.com/iphone/library/documentation/Cocoa/Conceptual/Multithreading