NSData *data = [[NSFileManager defaultManager] contentsAtPath:path];
in data is than the content of the file.
If you want specialized data, I recommend learning from the
NSCoding tutorial of the famous Ray Wenderlich.
I really encourage you to learn such stuff, because that makes Objective-C a very powerful and easy to work with language.
Very important are delegates and protocols, which work "as interfaces" to empower classes with needed features. :-O