This week's book giveaway is in the Mac OS forum. We're giving away four copies of a choice of "Take Control of Upgrading to Yosemite" or "Take Control of Automating Your Mac" and have Joe Kissell on-line! See this thread for details.
As far as I know, there's only ever one main method. Yes, you can access functions in one class from another class. It just depends on which access modifiers (Public, Protected, Private, (Default)) are in place.