http://forums.afterdawn.com/forum_view.cfm/62 Look at the guides in this section. There is one for almost every issue you can think of. If you don't want to go through all of the pages, then simply search the user submitted guides section for the specific task you wish to learn more about. Have Fun traveling the information highway to educationville.
Assuming the files are already on your hard drive, here's a guide: http://www.dvd-guides.com/content/view/40/59/
The question was so vague, that I'm not sure which format they are refering to. There are so many, so giving instructions on avi's will do no good if they are talking about actually ripping a dvd itself (and visa versa). Sorry if I sound short, I'm not trying to be. I just believe in stating the facts and you can't see a personality very well in type. oni123, if you were more specific, I could help more. There are also guides telling you how to copy the hard to copy dvds as well in that link I previously posted, so bookmark it (it'll come in handy).
Oh, well in that case... Rip it to your hard drive using DVD Decrypter http://www.mrbass.org/dvdrip/SetupDVDDecrypter_3.5.4.0.exe , or DVDFab Decrypter http://69.73.173.59/download/DVDFabDecrypter29.exe . The VTS file will be placed on your Hard Drive. Then Either use DVDShrink http://www.mrbass.org/dvdshrink/dvdshrink32setup.zip , or Nero Recode to copy the File from the location you save it to on the hard drive. Did I forget to mention that those programs are all FREE? Hope this helped.