Here you can find a good tutorial:
http://useyourloaf.com/blog/2010/05/18/adding-a-settings-bundle-to-an-iphone-app.html
Comes down to this: Add a file -> Resource -> Settings Bundle
If you only have 1 level, add the settings to the root list. Mind the Identifier, for this is the identifier user later on in the program to get it.
The in your app you can simply address the UserDefaults with the identifier mentioned above:
NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
BOOL enabled = [defaults boolForKey:@"enableRotation"];