Add button on UINavigationController

i'm trying to develop my first iphone apps. I'm using a navigationController with three views: main->first view ->second view. I would like to add a button only on the first view, i tried like this:

self.navigationItem.rightBarButtonItem = self.editButtonItem;

but nothing appear. If I add the button on the main view it appears after on each view, is possible to do what I want? Thanks!