Oh, a couple more bits of advice.
4 or 5 people sound like a lot.
Usually 3 people is the golden mark for broadcasting. It's enough people to make sure there isn't dead air, but there is a lot of time for everybody. 4 can work too, but can be troublesome since it may lead to some talk over... 5... i'd be worried there is too much talk over.
Which is another issue. The people in the podcast need to know the "Pecking order" so to speak. This is to prevent people from talking over each other, and a "side" personality trying to take over a show and in a lot of ways ruin it, take it off course etc. often without that person knowing it.
Which is why I talk about approaching people rather then asking for volunteers. People approached are more likely to respect and be able to understand the pecking order of broadcasting so the show flows nicely.
It should be known who should get the most talking time, who is the "co host" for said podcast etc. Otherwise it comes off disorganized.
Having a hierarchy so to speak to start off with will go a long way in starting the show off on the right foot.
Remember if you think the hierarchy should change because someone under or over performs it can always be switched up.
Oh, and also make sure to email the people ahead of time so they can do research. The last thing you need is a bunch of people coming in "cold" it actually takes a decent amount of research to be able to talk intellegently about some of this stuff.
