you can download 2 freeware programs that do basically the same things. 1 is mactheripper. this one is awesome, it does a really good job getting around the anti copy codes. When it puts the files onto your computer, it stores them as ts files. those are un compressed and you cant watch them on your computer(unless you have vlc which you can watch them individually). This means that it is the size of the dvd(either 4.22 gigs or more...thats alot) the second program is handbrake. this one is awesome because it can also get around some copy protected dvds and converts straight to mpeg or avi. You can also convert the ts files from mactheripper to avi or mpeg. So that takes up alot less room and once you have it in avi or mpeg thats easy to compress smaller. Both these programs are freeware so just search for them online.
hope this helps and if u have any questions just post back