Ripping the various files is not usually a problem, the challenge is circumventing the various forms of copy protection on most DVDs. You might want to take a look at this info from How-To Geek. I have not tried this, but I have feedback from my son who has and says it does work OK.

http://www.howtogeek.com/howto/20293/how-to-rip-a-dvd-to-your-hard-drive-and-play-it-on-your-pc/