title: How do I customize the controller for registration in Devise?
body: <p>I need to add some simple methods and actions when a new user registers through Devise.</p>
  
  <p>I want to apply a notify method which will send an email to me.</p>
  
  <p>I want to use acts_as_network to pass a session value and connect the new register to the person who invited them.</p>
  
  <p>How do I customize, I looked at the docs, but I'm not entirely clear what I need to do....thanks!</p>