Personally find Audacity easy to use.
MP3 is sort of the defacto standard. BBC and I think NPR as well put up the specs for what level of audio quality you have to have to submit something for them to use. Here is what I found on the
BBC Standard. I also found
this document on what NPR is looking for. That would be professional but, for most people exporting to an equivalent setting in MP3 using a more Voice centric export would work better.
That being said at NFR we record in a raw format, wav or whatever Audacity uses in the background, and export all are audio to the Lossless Flac codec so they can be imported by whoever edits the episode into separate tracks in Audacity.
In general for NPR it looks to mean:
Suggested MP2 file formats: Bitrate: 192kbits for mono, 384kbits for stereo. Sampling Frequency: 48KHz
Suggested WAV and AIFF formats: Sampling Frequency 48KHz or 44.1KHz.
For BBC:
Linear PCM, 44.1 KHz, 16 Bit in the Riff/Wav format.
For Podcasts its common to mix the audio down to Mono since its mostly voice, you lower the size, and people can listen with just 1 ear. That being said if you include music originally meant to be in Stereo it gets a little weird. We are actually thinking about moving to Stereo for that reason.
Hopes that helps some.