Depends what you want to turn the DVD video into. DivX or Xvid are great for keeping almost all the quality and reducing the filesize to fit it on a single CD (700MB). You may want to make a VCD or SVCD to play on most normal DVD Players. VCD is VHS style quality whereas SVCD is much closer to DVD but will take up more CDs than DivX/Xvid. Dr DivX is a program which specialises in ripping DVDs to DivX format, should be very easy to use.
If you want to duplicate the DVD (for a backup presumably) you should start with something like DVDdecrypter which strips the DVD of regionality and copy protection and dumps it to your HD (4.5-9GB usually). Then you could use something like DVD2One which can allow you to specify what you wish to copy from the DVD, this way you can fit it on a single blank DVD disc. I think then all you do is burn it (Nero?), maybe you author it first. I've never actually done it myself!