iPod can play only MP4 and H.264 video, in order to add DVD movie to your iPod, you need third party software to help you convert DVD movie to MP4 for your iPod. I stongly recommend this all-in-one iPod converter to you, it can not only convert protected DVD movie, but also AVI, WMV, MPEG, DivX, XviD as well to iPod format. This is the best ipod converter I have ever used. Here is a step by step gudie about how to use it
http://www.top5soft.com/video/cucusoft-ipod-vi deo-converter-dvd-to-ipod-suite.html
You can also refer to this unbiased iPod converter review
http://www.top5soft.com/ipod-video-converter-r eview.html
If you still have problem, feel free to contact me.