Over the years of annotating various DC series, I’ve found and used several sites. Those that are currently (September 2019) still around can be accessed by clicking on the logos below.
The site that got me started, Jonathan Woodward’s Annotated CRISIS ON INFINITE EARTHS.
A site hosting a whole bunch of annotations and bibliographies.
A site that uses the WHO’S WHO approach and is an invaluable source of info.
Fan driven wiki about DC Comics.
A Wonder Woman fan site that was really useful when completing the WAR OF THE GODS annotations.
The Comic Book Database that’s been a great resource over the years.
The Green Lantern specific fan driven wiki.
A site that puts various events into a coherent reading order.
The Grand Comics database which is exactly what the name implies.