The first thing that you need to do is to get in touch with an event organizer. Now the event organizer is going to be crucial to you and your event. This organizer based on your instructions is going to have to go on and get the location wrapped up for you. Getting the right location is very important, since you don't want to book a place that is far too small for your audience.
At the same time, you need to get the even planner to go on and set up the venue for you. They are going to have to take care of the seating and the basic layout of the whole place as well.
With the location taken care of, the next thing you need to do, is to get all the artists on board. You need to tell them exactly what is going on, so that they have ample time to prepare for it. You can give them some basic guidelines over what they can answer, and what they shouldn't be answering. This way, they will be better prepared for the panel and any question that is thrown at them.
On the day of the event, go ahead and start off by basically explaining the project and what the artists have done, you may display some images as well, should they seem to make sense and fit in with the presentation.
Now after this basic introduction that you have given, you can now go on and let the panel get questioned by the audience, however, don't let any question take too long, since you are going to want to answer as many questions as you possibly can in the time that you have.