Exporting for distribution
MP3, 96 kbps, constant bitrate, 44,100 Hz, 16-bit. That's the spoken-word default. Save those settings as a preset and stop thinking about it.
Podcast episodes are almost always released as MP3. WAVs contain more detail (they're "lossless") but they're huge — think of a WAV as the original painting and an MP3 as a print. Only a handful of people on Earth could tell the difference for spoken-word content, and MP3s keep storage and bandwidth costs down for you and your listeners.