An easy way to share your podcast is to have it listed on the iTunes store. This doesn't mean it costs money to download or that it is hosted by apple, just that it is in the directory that users can browse via iTunes.

There is an excellent online tutorial to guide you through the process. For all the nitty-gritty detail check Apple's technical specifications. These are pretty complete, but there are three points I'll add:

1. Your submission will have to be approved by an actual person, so it may take up to 7 days before your podcast gets listed. Therefore, start early.
2. The iTunes store will check your podcast feed once a day to update its database. If you publish something and you want it updated on iTunes immediately you will have to "ping" the iTunes store to let it know to check it right away. To do this enter https://phobos.apple.com/WebObjects/MZFinance.woa/wa/
   pingPodcast?feedURL=http://FEEDURL
   where FEEDURL is the url for your feed into your browser. (note I have broken this long URL into two lines - you will need to reasseble both lines when you cut and paste this into your browser.)
3. Once submitted, you find your podcast by searching the podcast section of the store for any of your title or keywords. Right-click on the podcast and select "copy music store URL" to get a link that you can put on a web page that will open the podcast directly in iTunes when a user clicks on it.