If this video tutorial (in which you wrote zero code) is you're only experience with XCode and Cocoa programming, then this is beyond you, because you can't just drag a connection between the New menu item and something.
If you do know Cocoa programming then:
- Create a new xib file in your project called window.xib.
- Cut and paste the window from mainmenu.xib into window.xib.
- Create an newWindow: action in your app delegate that will load window.xib using NSBundle's loadNibFile:externalNameTable:wihtZone: and then send makeKeyAndOrderFront: to the NSWinow.
- In your app delegate's applicationDidFinishLaunching:, send newWindow: to self.
- Reconnect your menu items in MainMenu.xib to the First Responder object.
If you've never loaded a nib file programmatically, see the Nib Files chapter of the Resource Programming Guide.
Like your current version, this won't be perfect. For example, the web view must have focus for File|Print to print the web page. If focus is in the text field, for example, text field will print instead.
And you might be leaking memory with unreleased window objects. I don't know about this. I've never used a window without a window controller.