1) Phone or landline to record sound from guests. 2) Microphone of any sort for the presenter to record their side sound - this is essential, and a cheap USB microphone will suffice. 3) Software such as Audacity, GarageBand, or Adobe Audition. 4) Internet connection with good bandwidth/upload speed 5) Headphones (not speakers) for the recording person to monitor themselves. Speakers create an echo which it's best not to have on your recording.