Things change rapidly in the WordPress world. The content in this post is more than a year old and may no longer represent best practices.
Two places to do live “talk radio” shows on the Web are Talkshoe and BlogTalkRadio. You can download the files and edit them afterwards, but the quality of the original recording is not going to be very good. Note that Talkshoe produces shows with no ID3 tags and BlogTalkRadio puts “BlogTalkRadio” into the “album” field for all its shows, making it hard to differentiate.
Mp3tag is a universal ID3 tag editor for Windows to help you fix that. You can also edit ID3 tags in iTunes. Unlike every other RSS reader and podcatcher, however, iTunes uses your blog author name and blog title to overwrite your ID3 tags when they distribute your file, just to be annoying.
Confused about podcast subscription? Learn to subscribe to a podcast in iTunes with this video by my friend Dave Jackson: http://www.learntosubscribe.com/
Feedburner can give you some additional statistics about who is subscribing to your blog feed and also who is downloading your podcast episodes. It can also be helpful if you change locations for your blog, especially if you change domain names (e.g. from myblog.wordpress.com to myblog.com). But it’s not necessary: WordPress creates perfectly good feeds by itself. There are WordPress plugins to help make it easier to use Feedburner.
Google Listen lets you subscribe to podcasts on Android phones.
There’s a Podcasting app called Podcaster that lets you subscribe to podcasts on the iPhone. Many podcasts have individual apps, as well. These often include ways to comment or call in.
Tom Abate mentioned the Soundslides software (commercial, Mac and PC) for creating narrated slideshows. It creates Flash (.swf) presentations for embedding. All well and good if you’re not looking at the shows on an iPad, of course…
You can also use SlideShare to create a “slidecast”. If you have an MP3 audio recording and a set of slides, you can sync the recording to the slides. We’ve done this before with slides from the Meetup. Slidecasts can be embedded like other SlideShare presentations. (Just copy the embed code and paste it into the HTML editor in your WordPress post, or use the SlideShare plugin by Joost de Valk.)
Something I left out? Post it to the comments.