It's free. You may have slight costs (editing, tags, hosting, etc.). We just host it ourselves, and we feed using feedburner, launching from a wordpress blog.
You can do a blog like
this
Or you can link to a feed like
this
Or, you can put an image link on your blog like
this on the upper right hand side, look for Romans icon
Or, lastly, what's called a splash page like
this
It also helps if you make them available for free. You'll also want to "tag" them, which simply means and intro (with music) and an outro (with music), both with a second voice.
Intro: You're listening to the ABC hour with our guest, XYZ.
Outro: This has been the ABC hour with XYZ, join us...visit us on the web @... etc.
If there are any kids at your church, ask them. They'll know how to do all of this stuff on their mac!
Hope it helps. We chose itunes over SAudio, but may add SAudio soon.