there are two software suggested.
one is freeware, named videora converter+ DVD Decrypter. First rip DVDs to video formats with DVD Decrypter, then convert created files to ipod video with videora converter.
the other is xilisoft dvd to ipod video/audio converter, one-stop dvd to ipod software. download at

http://www.xilisoft.com/dvd-to-ipod-converter.html