Just put groupboxes ("BUTTON" class windows with the style of BS_GROUPBOX") around the controls that go in this "pane" or that "pane".
For multiple windows, just create do what you normally do with one window, but create 2 instead of 1 before entering the message loop. Each window should be it's own class, also keep in mind that issuing a quit message (PostQuitMessage()) will break the message loop for BOTH windows then.
