Prehistory of the D.C. Universe
The revised, post-Crisis history of the D.C. Universe.
Notable works that span great swaths of early D.C. history, but are being omitted for the time being:
The History of the D.C. Universe I & II
by Marv Wolfman
; the timeline of events summarized after "Crisis on Infinite Earths"
The Atlantean Chronicles
by Peter David
; miniseries chronicling Atlantis from it's foundation through the birth of Aquaman