There are a couple of things you can do. You can either rip the disk to your HDD in ISO mode, and mount the ISO using Daemon Tools or something to play it. You can also rip the DVD in File mode, and just point whatever DVD player you use to the IFO file to play the DVD.

Either mode will give you an easy route to crushing the DVD down to a smaller size using DVD Shrink.

If all you want to do is play the DVDs, just rip to your disk, and use DVD Shrink. After DVD Shrink, you'll end up with directory with all the files you need to make the "new" DVD. Just point your player at the IFO file for the full DVD, and play away.

Hope that helps.