I wanted to get the soundtrack off a DVD my sister made (i.e. she produced it, not ripped it). Any way here's a good tutorial: http://www.glump.net/content/audio_dvd_rip/guide.htm#cutting
Basically the programs used were Smart Ripper (to rip the audio from the dvd) and HeadaAC3he to convert the file to wav (you need HeadAC3he, Libmmd DLL, Azid DLL, SSRC DLL). Then I pulled it into Nero SoundWave and chopped it up appropriately. Nero Sound wave won't handle the AC3 files Smart Ripper produces directly, I tried.
(I'm putting this here in case I ever need to do this again, I won't have to google it.)