the wiki is alright, but there is a lot missing. Also, it could seriously use some updating with all the sourcebooks out there. I think recurring elements (tieflings, dragonborn and their respective empires' history) could easily have their own sections. For example, a list of the PPs coming from Nerath, Bael Turath, Arkosia, etc. could easily be included in that entry. Likewise, the more prestigious characters from the various books released would be a nice sight: Vecna and named accomplices; demon princes and archdukes of hell; the Prince of Winter in the Feywild section.
I recommend, however, having this info as a backdrop the PCs are aware of, and developing only what you're going to *use* in an arc. Maybe explore a feud between dragonborn and tieflings, or gnomes and fomorians. Mention Nerathi ruins. Or have roadside shrines like in the wiki, as the site of a robbery or something.