go to www.wikipedia.com and search on Podcast and Podcasting.
There are a plethora of information out there about how to podcast.
You can use www.odeo.com to set up your own podcast and might even have some recording software on there. If you have your own website or access to some space, which might work, you can use Wordpress (www.wordpress.org) and Podpress (www.mightyseek.com), which is a plug in for Wordpress that makes the blogging software a Podcasting friendly interface. You can also pay 5 bucks a month and use Libsyn (www.libsyn.com), which is your hosting service and website (easy to setup) and is not that expensive. It also works with or without a domain name. I use them. These 3 should also take care of the RSS for you, making it simpler.
You can also check out AudioHijackPro, which I think can record Skype, but not sure as I use HotRecorder, which I would not recommend for recording from Skype. There are technical issues.
I have my own podcast at www.painbank.com and have been doing it since Nov 2005.
Yes, Audacity is free and can be used for recording.
there is a ton of stuff you can do, only some of which is free, but once you get into a bit, you will probably not mind spending the money. My suggestion is to also buy a book on the subject, which can help tremendously for ideas as well as how to do it. I have O'Reilly's Podcasting Hacks, which I would recommend.
iTunes acts as a podcatcher and will receive any updates if you have subscribed to the RSS feed of ANY podcast not just Podshow.
