The Story Reference section of this site has lists describing and identifying people and places of interest to the story.

The Heroic Personae describes the principal adventurers of the Dark Mysteries Campaign, as portrayed by their players.

The Other Personae lists the myriad of lesser players within the Dark Mysteries Campaign.

Taverns and Inns describe a number of the venues that the adventuring Heroic Personae have visited over the course of their many adventures.

The adventurers have also traveled aboard a variety of Ships, as well.

No medieval adventure would be complete without Castles and Strongholds.

And, let us not forget the Kelltic Calendar that is used throughout the original campaign.

One thing to note: as the World of Oerth goes through some significant revisions, there likely will be some name changes and other such tweaks taking place that will cause something of a divergence with the official story writeups.  I may, at some point, go back and retroactively tweak elements of the original story to match them up with updated Oerth, but that is not yet a top priority.