Denis McGrath is in the middle of a series of posts on his blog about the system of writing in the US and Canada.
He's following the scripting process on an ongoing television series from beginning to end, looking at the various drafts and documents you turn in, and who they go to. Why you shouldn't put dialogue in your treatments. And at which points in the process you can get away with putting in a bit of handwavium.
More to come, so stay tuned to his blog.