How does DVD anti-piracy work?
There are many copy protection schemes in use, explaining them all would be a long post, even if I knew how they all worked.
Obviously the companies that use them want to keep them a secret so it's harder to bypass, so you probably won't get much information from them.
You best bet is to check the CD/DVD copy forums, users there would have done some analysis to find out the best way to copy them.
General info
Club MyCE forums
Afterdawn forums