This document will give you step by step directions with images on how to use the Mac based program Garageband to create a mv4 (an audio recording with still images) that can be uploaded to a host site to create a Podcast. I have another document titled "Posting your Podcast" which shows how to upload the finished file to iTunes for student downloading.
Once you're familiar with how to create the file, you can even use this handout to have students create their own mva files.
Sorry PC users, Garageband only works on Macs. However, you can create your file in Windows Media Maker and Post your podcast using the same directions for Mac users. See my document titled "Posting your Podcast"