I picked up Kent David Kellys Castle Oldskull bundle a couple of months ago. Included in were Kelly's histories of Dungeons and Dragons "Hawk and Moor" (I actually have had Hawk and Moor 1 for a while but never read it). Kent has assembled from the web discussions and comments on the early days of D&D to write a narrative history of those days. It is interesting to contrast this with Jon Petersons "Playing at the World" which more based on written documents from the actual time period. Both methods seem to have their strengths and weaknesses. For covering the interplay of the evolution of rules and who did what when Peterson's approach is better. For descriptions of actual gameplay in the early Kelly's approach is better, as it is relying on web post by people who were actually there. In summary here is my review"
Hawk and Moor 1: Interesting but this subject covered better in Jon Peterson's "Playing at the world"
Hawk and Moor 2: Better than volume 1. This goes into recollections of actual play in the Greyhawk dungeon. Since it is compiled from recollections and internet posts of 2000's, it is perhaps colored by the vagueness of human memory. However, it is probably as close to the original Greyhawk experience as any of us will come.
P.S. I'll try to get to the actual Castle Oldskull books sometime later.