Not sure what information you need, but here's what I got.
Taken from a tutorial here: http://www.gamedev.net/reference/articles/article608.asp
/*
* The cooperative level determines how much control we have over the
* screen. This must at least be either DDSCL_EXCLUSIVE or DDSCL_NORMAL
*
* DDSCL_EXCLUSIVE allows us to change video modes, and requires
* the DDSCL_FULLSCREEN flag, which will cause the window to take over
* the fullscreen. This is the preferred DirectDraw mode because it allows
* us to have control of the whole screen without regard for GDI.
*
* DDSCL_NORMAL is used to allow the DirectDraw app to run windowed.
*/
ddrval = lpDD->SetCooperativeLevel( hwnd, DDSCL_EXCLUSIVE | DDSCL_FULLSCREEN );
I also found that SetCooperativeLevel must be called before SetDisplayMode.
Also this might or might not be helpful:
http://www.eggheadcafe.com/software/aspnet/33936361/idirectdraw7setcooperativelevel-and-focusdevice-window.aspx
For pure documentation I couldn't find anything better than MSDN, so old SDKs are probably your best bet if the above doesn't cut it.