Please help me learn to teach Podcasting

Please help! I have an hour on Saturday to teach the Music SIG at Apple Corps of Dallas how to record a Podcast using a Mac and GarageBand. I understand the very basics of doing this, but I've never actually done a Podcast before. I've only used GarageBand to record music and pretty amateurishly at that. So, can you veteran bloggers and podcasters post some comments on my blog with links or suggestions for Newbies on recording Podcasts? I'm very interested in the workflow that you use when you sit down to create a podcast. Are there any tips and tricks on mixing an mastering or any special plug-ins that you use? Where do you get your music and when to use music in a Podcast to enhance not detract from the message? Where do you host your podcast and how expensive is it for a beginner? Please feel free to post links to tutorials or plugins and share your ideas so I can pass them along to the SIG. Again, this is for my Music SIG at Apple Corps of Dallas, the oldest Mac User Group in the country, nay the world!