Im not a big tech junkie but heres what i know/do.
I would do 1 of 2 things...
1. google or yahoo search or whatever to find a program that would allow you to rip dvds. and im not even sure that that would work because i think dvds have like special thing on them so that you cant unless u have certain hardware. either way just do a little research about it by google-ing it. thats what i did for Audio editing programs.
2. I use a program thats called BitComet. I go to the website- www.isohunt.com. I download MP3s and even a couple movies. you just have to make sure its in the right format. they might even have a program you can download onto your computer for DVD ripping. If you go this route it may take a while to download depending on internet speeds. If you find a WMV movie format (i think thats right but im not sure) you can just download it onto your computer onto like windows media player or some other program.
Im not a tech junkie so im not sure exactly about DVD ripping or how its done. But downloading it is what i do. And that website is completely FREE! no lies. i use it all the time for my music downloads and i have tons of music.
I suppose this didnt really answer the 'how to rip DVDs' but im not sure its possible with out a certain devise even. all i can say is either 1. research to see if its even possible with a special program and then download the program or 2. just download the movie in a certain format for your Ipod or MP3 player or whatever you have.
good luck