You learn a great deal about what goes on behind the scenes at "The Simpsons" by listening to the commentaries on the DVDs. When I get a season of "The Simpsons" on DVD, the first thing I do is watch each episode once with the commentary on, which irks James but pleases his father. There's a great deal of insight into how a concept evolves into an episode and I find it fascinating.
I just read an article by Mark I. Pinsky entitled ""The Simpsons": Behind the scenes of an episode" which fellow Simpson fans will want to read as well. Lots of neat tidbits and even some jokes from a future episode.
The table reads sound amazing.