First, get this. It'll unlock copy protection.
Or get this which will convert DVD's to mpegs if they are too large to find onto a standard 4.7 GB disc, which seems to be the case with most of them.
DVD to DVD Copying
Alternatively, get DVD Shrink, with just two clicks (one on Open disc, and another on Backup), providing you have Nero (or maybe similar, root around the site for more details), and the vast majority of DVDs will be copied.
If a disc in encrypted refer to the DVD shrink site.
If a disc in encrypted refer to the DVD shrink site.