[C#] How to code within the Unity 4.6 new UI Panels?

Alright, I have all my UI setup the way I would like it. I have buttons that open up Panels, as well deselecting these panels. Now the problem I have is how exactly do I use code with these prompts. Like I have a singleplayer button that opens a panel, and I want this to show options and toggles. Perhaps I can use the GUI elements again, but how to use the code that has to access this information?