Step 1: Add AVI File(s)
Free download and install DVD to iTunes Converter. Click the "Open File" button to browse your computer hard disc and add the AVI files you want to convert to iPod.

Step 2: Output settings
After you add AVI files, you can select an output format for each video file and specify a directory on your computer to save the output files. If you don't know what formats your iPod supports, you can just select the format according to the iPod name.

Step 3: Convert AVI to iPod
Click the "Convert" button to start conversion and then you can just go out for a walk or take a nap, and the conversion may have been finished when you come back.

Releated Guide: How to Put Videos on iPod?