The content on the DVD is likely copyrighted and using such programs to strip the contents would be illegal. If you avoid piracy, you'd be best off paying for a download, from services such as Vongo... I think they allow you to put it on your Ipod.
I'm going to be naive here and assume that just because it's on a DVD doesn't mean it's a commercial DVD and you have rights to do what you plan to do.....since you never said what DVD it was =^.^=
Well, since Darkhunter deleted his post for some inexplicable reason after I edited out the direct download links for legal reasons:
He suggested searching for DVD Decrypter. Can't link to it here, I'm afraid, but if you have a private chat with Darkhunter about it...well...that's nothing to do with me
It will come with a warning, because depending on your country/state, installation and use of it may be illegal
You would also need something to convert the DVD VOB files into a suitable file for your Ipod.
Perhaps a look round videohelp.com might be of use to you