The 4,000-page “Gray Book” collection of Fleet Adm. Chester Nimitz communications that started with the the Pearl Harbor attack and were kept through the end of the WWII is now available online.
Here's the Description:
The Command Summary of FADM Nimitz was compiled by the War Plans Section of the Pacific Command Headquarters in Hawaii during World War II. It contains daily estimates of the situation, command decisions, and running summaries of communications from December 7, 1941 to August 31, 1945. Naval War College Historian Douglas Smith avers that it is "the most authoritative source on the Pacific War available anywhere".