Yes, you can, But iPod accepts only MP4 format video, DVD is MPEG-2 format, so you have to rip your DVD to iPod format, then you can put it on iPod. I always use 'Wodnershare DVD to iPod Ripper' to do that, it works well for me, you just need to put your DVD disk on your drive and strat conversion, then you dvd will be transfer to iPod directly, Very easy to use, you may download it for a trial.
http://www.dvd-ripper-copy.com/download/dvd-iP od-download.php?sid=2
Here is a step by step guide about this software
http://videoguys.forumexperts.com/viewtopic.ph p?t=111814
If you are Mac user, you can use 'handbrake', it's free and fit for Mac OS, here is the download link
http://handbrake.m0k.org
Here is a step by step guide about it
http://www.top5soft.com/tutorial/convert-dvd-t o-ipod-with-freeware.html
I hope it helps.