I tested out the USB Microhpone Samson Meteor Mic (2016). It connects to my laptop via a USB cord. I opened up GarageBand and started a new Audio/Voice Project. There are many different vocal effects options, but I just used the basic “Narration vocal”. Press the red circle record button to begin, and press again to stop. After you are done recording, you can edit the vocal recording.
Then, you save it in GarageBand. Then, you can “Share” it to iTunes. It will be saved as an .m4a.
In iTunes you can convert the file to an .mp3 by opening it in finder, and then just changing the .m4a into .mp3.
Here is the link to the Podcast test:http://owl.fish.washington.edu/scaphapoda/grace/Podcast/Podcast-test%20-%202_5_18,%205.55%20PM.mp3 I just uploaded the .mp3 to my Owl folder.