Edit: Beware, there are MAJOR (novel ruining) spoilers beyond page 1 if you follow the link.
There's some great stuff in this article about the process of putting the novel together. But I think some of the best lines in the novel are revealed and it's just not worth reading them in this context. Also, I disagree with Grossman's reading of Infinite Jest... although it's not anything that hasn't been said before.
Wallace's papers for The Pale King form a remarkable record of an idiosyncratic mind at work. He began by taking notes in, apparently, whatever notebook was within arm's reach; one of them has a Rugrats character on the cover. He switched pens practically every paragraph. The notebooks contain scattered words, character names and observations, as well as what appear to be personal admonitions. (One note reads: "If I wanted to, the solution is to get up early and go to the library.") They're chewed over and bent and practically charred by the intellectual energy Wallace expended in them. When Pietsch finished his survey, he had found a total of 328 chapters and drafts and fragments from The Pale King, but Wallace had left no clues as to how they fit together. At that point Pietsch's role skewed from editor toward collaborator. "It took me quite a long time to read all of that," Pietsch says, "and take notes, find the latest draft of every chapter, read it all again, find the things that made sense together and discover that there was a central chronology, which was not at first apparent." Pietsch organized the chapters in a spreadsheet, sorting them by type and character, choosing among multiple drafts and arriving at a tentative order from circumstantial clues. He edited the actual text as little as possible, but some chapters didn't have proper endings — they just trailed off midparagraph — and Pietsch had to choose a spot and then snip them off cleanly.