While DreamOutLoud13's method works, it is rather tedious and time-consuming(since you have to watch/listen to whatever you're recording while recording it). There is another method which, while it may initially look more involved and complicated, is easier and more efficient in the end, imo. Rather than recording as it plays, you actually rip the tracks from the DVD that same way you would rip tracks from a CD.
1.Download 'DVD Decrypter' form
http://www.mrbass.org/dvdrip - the link is in the second line of text below the title banner.
2.Open 'DVD Decrypter' and insert your DVD into your DVD drive.
3.In 'DVD Decrypter', go to the 'Mode' menu and click 'IFO'.
4.Go to the 'Tools' menu and click 'Settings'.
5.In the 'Settings' window, click the 'IFO Mode' tab.
6.You will see a drop-down box with 'File Splitting' next to it. If you're extracting audio from a DVD, chances are you'll want to divide it by chapter(a scene from the scene select menu on a DVD), so select 'By Chapter' from that drop-down box. Click 'OK'.
7.In the main window, you'll see two tabs on the right side: 'Input' and 'Stream Processing'. Click on the 'Stream Processing' tab. You will see a checkbox with 'Enable Stream Processing' next to it. Check the checkbox.
8.In the subwindow just below, you will see a list of 'tracks'. There may be more than one audio 'track', but there will hardly EVER be more than one video 'track'. UNCHECK the checkbox next to the video track. That's all you have to do here. Now, click the 'Input' tab.
9.In the subwindow under the 'Input' tab, you will see several volumes. Generally, there will be a volume from the main feature of a DVD(the film/concert), and a volume for bonus features. Sometimes the bonus features will take more than one volume. Each volume you see will have a +/- thing next to it so that you can see all the chapters(scenes or songs) within the chosen volume. At this point, you have to select which chapters(scenes or songs) you want to extract audio from. They are ONLY labled by number in DVD Decrypter, so you may have to fire up a DVD application or look inside the DVD's case to match a number to scene/song. Select as many scenes/songs as you want(there will be a checkbox next to every single chapter - simply check the checkboxes next to the chapters you want).
10.When you have everything, selected, click the big button on the bottom left-hand corner(the DVD-arrow-Hard Drive graphic). 'DVD Decrypter' will extract the audio from your DVD now....but in .VOB format, the native format of DVD media. So what now?
11.Download an IPod video converter - doesn't really matter which one as long as it works. I recommend 'Videora IPod Converter' -
http://www.videora.com/en-us/Converter/iPod/download.php .
12.Use the IPod video converter of your choice to convert all of your extracted .VOB files to .mp4 files.
13.Import the converted .mp4 files into ITunes.
14.Now, select all of your imported .mp4 files in ITunes, right-click on them, and convert them to AAC.
15.When that's finished, delete all the .vob and .mp4 files - the AAC(. m 4 a) files are the finished product.
16.Add whatever info you want to your files in ITunes.
You're done. Note that steps 1-6 will only have to be done the first time you do this, as those settings should be saved. Also note that once you get the hang of this, it's much simpler than it looks.