rknop
|
The best quick overview is probably the Inner Sea Primer
There is always the problem, though, that when a player asks you something, you can't necessarily be sure if the details of that place have been written up somewhere yet. You can always make stuff up that's consistent with the general tone of the place (that's part of the fun of GMing), but then you might find yourself later at odds with printed stuff. (Which is OK-- you make it your own world when you GM in it, as long as you're not doing PFS-- but then you have to keep track of all of that if you want to be consistent.) There's a lot of information out there!
The wiki is definitely a very good resource for quickly looking stuff up.
By and large, you can guess in which books you might find information about things. E.g., you can quickly find out if the city your players are going to is covered in Cities of Golarion and so forth. (The greater uncertainty is if something's received attention in one of the adventure path issues, because then the title of the work isn't a tip-off to the fact that that topic might be in there.)
I don't suppose anybody's made a master index of Golarion, which says which places, people, events, etc., receive substantial attention in which Paizo publications? You can sort of get that from the references on the Pathfinder Wiki, although they tend to be "complete". (This is what you'd want -- but it does mean that from the references, you can't necessarily tell which things cited just mention a given topic, and which ones contain a lot of information.)