Did you export the project as an mp3? Audacity creates project files and data, but you need to export your project as an .mp3
If you've done that, then you need an rss/xml feed for your iTunes to locate.
It sounds as though you are trying to keep everything on your local computer? (Which is somewhat odd since most podcasts reside on the web?) If so, you can try something like this:
<title>This is LinkinPark's Set of Podcasts</title>
<link>This is a link to a page that talks about LinkinPark's Podcasts</link>
<description>LinkinPark's podcasts offer wonderful perspectives on baking cookies</description>
<copyright>LinkinPark's Podcast 2005</copyright>
<title>This is my first podcast</title>
<description>I talk a little about selecting the right dough for my famous chocolate chip and crushed grasshopper cookies</description>
<pubDate>Thu, 28 Jul 2005 03:12:07 GMT</pubDate>
<enclosure url="link/to/the/podcast.mp3" length="55555555" type="audio/mpeg"/>
The key thing your iTunes is probably looking for is the enclosure url and the above rss feed.
You will need to put in the correct url for your podcast and you will also need to determine it's length. This can be done by right-clicking on the .mp3 and clicking on properties. This will tell you the length in bytes.
You can probably just copy the above code into notepad or similar program, make the changes to reflect your podcast and save it. Then change the file extension to .xml This will then be your rss/xml feed. Open up iTunes and look for it.
The above should work, but I've never tried it myself. (I don't have a portable media device)
You said you wanted to make the recording into rss form, but that's not really what you want. You want an rss feed that will include the correct tags for your podcast.
So, to sum it up:
iTunes is probably looking for an rss feed.
You can create that feed in a text editor like notepad. (Or do a search on your favorite SE and search for "podcast rss generator")
Double check that all tags are correct. Specifically the enclosure tag.
Rename the file extention from .txt to .xml
Point iTunes to the feed.
Let us know if this works?