Hello JSW W.,
To be able to load previously saved state all you need is when the panels and documents are created to set uniquely their Key and Text property (only to NDockingPanel and NUIDocument).
To load the saved state you need to call one of the three overloads of the Load methods.
Finally, you should add the hosted controls in the panels or in documents if they are not there already.
Usually, when load a state the panels and documents are already created together with the controls that they contain, and you don't need to add them again.
Regards,
Angel.