You can read about CSS on Wikipedia. IMO it's a joke and I would advise you not not bother with it or any other form of obnoxious DRM.
If you still want to go ahead, are you willing to pay a license fee per disc? CSS key sets are licensed by the DVD Copy Control Association to manufacturers who incorporate them into their discs during the pressing process. CSS keys can only be added to discs replicated from the glass master. The keys are stored on the lead-in area of the discs, on tracks that are not even recordable on DVD-Rs/DVD+Rs. Even if they were, the firmware of normal DVD writers sold for home use is restricted from writing information to those tracks.