as ipod accepts mp4 format, you just need a converter that will go from dvd to ipod mp4 and then transfer the output mp4 videos to your ipod with the sync of itunes library. I prefer using clone2go dvd to ipod converter as it combines three main features into one program:

1. rip dvd to ipod
2. convert video to ipod
3. download youtube videos to ipod

here is the step by step tutorial that shows you how to rip dvd, convert video and download youtube video to ipod:

DVD to iPod guide - How to convert DVD movie to iPod Touch/Nano/Classic