To add to Bill's procedures for Macs, I'd recommend the free tool Handbrake
(again, google it) - it can rip a .mp4 video directly from a chapter/title
of an encrypted DVD. The .mp4 can then be manipulated in Quicktime, played
on an iPod, embedded in PowerPoint or Keynote, or burned onto a clip DVD
compilation, thus saving a step in the process.
And again, if you're a film/media faculty member doing this from a DVD in
the academic library you're affiliated with, it's totally legal!