Here's a little tutorial i wrote for another user a few days back.. :
First, you need DVD Decrypter, and Videora. DVD decrypter is illegal in the US, as it cracks the protection on the DVD. Click my name (<<< over there) and send me an e-mail and i'll send it too you. Once you have DVD decrypter, install it and insert your DVD (assuming you have a drive that can read DVD's) and press the decrypt icon. The process takes around 20-30 minutes. Then, google VOBmerge, and download it. Open it up, and find the folder that your DVD was saved into. Find that, and go into the video_ts folder, select all apart from the video_ts.vob file, and click Settings. Tick the box, as this will delete the individual files afterwards, leaving only the file that you created. Get videora and open it. Click settings and select a folder to save your converted files to. Select the file that you just joined together. I suggest doing this overnight, as it pretty much will render your PC useless (it does with mine, mine isn't exactly slow either). Change the profile to music video's, as this will make sure the audio is in the right place. After this has finished, delete the original files the came from the DVD (the .VOB files. These are massive, and will eat your hard disc!) The end result is a much smaller file. Add this to your library, and update your iPod, then enjoy watching your DVD's.