To convert a DVD and run it on your iPod, you're going to need a software conversion tool and a copy of iTunes on your computer. iPods that use video use the MPEG4 format of video and a H.264 codec.
There are a couple of solutions and conversion methods to watch your favorite movies on your iPods.
1. There is an old, longer, 2-step process which involves converting your DVD from DVD format to .avi files, and after that, you convert those .avi files to .mov (Quicktime) files. The final step of the process is for you to upload the file to your iPod from iTunes. However, this process takes alot of time to complete, and the quality of the produced movie is often very poor, so don't even bother with this method. Method number 2 is much faster and better, it involves some money spent (but it's well worth it, trust me), or you can get away with it for free, with reduced quality...you choose :).
Second method involves getting a DVD to iPod conversion software. You can purchase one, or get one for free. I don't recommend using a free software, because the quality of the produced iPod movie will almost always be fairly low compared to the ones produced by some software that costs. Nevertheless, if you are broke, but you just can't survive without placing DVDs to your iPod ( :) ), then you could try a free iPod Video Converter software.
Free iPod Video Converter 1.32
If you can afford a paid alternative, then do so. When looking for a software that will meet your standards, be sure to always look for speed, audio and video quality above all. Note that I mentioned audio quality. Don't forget that you'll be converting audio, as well as video, because most of the movies consist of video AND audio. Make sure that the software is also easy to use, because some converters come with advanced features that will make your head explode.
The best convereter I always recommend to someone is always Avex DVD to iPod Video Suite. It's a one-click all-in-one solution to make iPod movies from DVDs, TV shows, and every other possible format. The whole suite comes in with 2 converters (one which converts only DVDs to your iPod, and the other one which converts all possible formats, such as AVI divX/xVid, WMV etc. to MPEG4, which is an iPod format) which cost $29 each, but if you order the whole suite, you get it for $45. Avex DVD to iPod Video Suite is a great, easy to use tool, and you wont fail if you purchase it.
On the other hand, if you only convert DVD files to your iPod, you can get only Avex DVD to iPod Converter. It's great, fast, and produces movies with great quality.
After converting your DVD movies to iPod format, you will need to load them to your iPod. To do this, download and install Apple iTunes for free. If you already have it, skip this process.
After installing it, start it. Then, drag the MP4 or .mov file you've converted into the iTunes Library, and select the move you desire. After that, just load it into your iPod. Enjoy!