It's relatively easy. Set up an rss feed with appropriate enclosure.
I had a podcast set up last year, but it failed.
I'm not big on the details of xml so I used a free site that promptly shut down a couple days before our first episode. I got distracted after that.
If I did it again, I think I would host my files on archive.org and used a RSS feed generator to manage it myself. There may be better ways, but like I said, I lost interest a year ago.
I haven't used this site before, but it looks like it might fit your needs for generating the RSS.
http://www.tdscripts.com/webmaster_utilities/podcast-generator.php

Wordpress has a Plug-in that handles Podcasting rather well, and will even automatically add your Podcast to iTunes directory.

Of course, that assumes that you're using Wordpress. You might try creating podcasting subdirectory on your site, install Wordpress, and use it only for publishing Podcasts.