Over the years of annotating various DC series, I’ve found and used several sites. Those that are currently (May 2017) 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.
Making a damn good stab at putting every DC story into a chronological order.
Fan driven wiki about DC Comics.
A Wonder Woman fan site that was invaluable when completing the War of The Gods annotations.
The Comic Book Database that’s been a great resource over the years.