I think you are a bit confused.
If you want to use storyboards in your project, you don´t need to create separate xib files (at least for now)for the viewcontrollers you want to manage inside the storyboard.
In Xcode interface builder you simply drag a viewcontroller from the object library to the sotryboard, you can find it at the bottom of the right panel (the utility panel) .
Once you have your visual viewcontroller on the storyboard you need to asociate a UIVIewController subclass who can manage that viewcontroller. you do so by selecting the viewcontroller on the storyboard and selecting the identity inspector on the right panel (again the utility panel) then in the textbox next to the word "class" you write the name of the class that will manage that viewcontroller (if you´ve already created it).
Now you can make the connections of the viewcontroller´s subviews and YourUIViewcontrollerSubClass.h and create the properties you want to handle in code.