Since Alan won't be on camera for this, Leo recommends getting the Audio-Technica AT2020USB. The advantage of this microphone is that it's a USB mic, so he can plug it directly into his computer. Alan will need screen recording software next. For this, Leo recommends TechSmith, which offers two different programs. One is the less expensive Snagit, which is more basic. There's also a more expensive program called Camtasia Studio, which has more features but costs more.
Alan also wants to have someone on the webinar with him remotely. Leo says Skype doesn't record both sides of the audio, so he'll need a solution that will allow him to record both. A good screen capture program might do that, but Leo recommends Pamela, which is a Skype call recorder.