The New York Times interviewed Stephen Colbert on stage. Among other things, he describes his typical working day, and what goes into producing The Late Show. I haven't watched the whole thing yet, but what I've seen so far is really good.
I had the privilege of being on the Colbert Report twice. Each time, Colbert came into the green room and spent about 20 minutes chatting with me. He was really nice. I also noticed that the crew adored him and had a great relationship with him.