Arelith

For those who are interested and didn't already know...

http://www.candlekeep.com/
http://forum.candlekeep.com/

These forums are participated in by both fans of the Forgotten Realms universe and quite a few of its authors in an effort to compile hard to find lore of the realms and in general help people expound on things that are implied but not written within the books sometimes.

If you have a burning desire to dig up some obscure information about the world you're playing in to further some concept or narrative you're aiming for, this is a good place to do it- there's a chance the question may have already been asked, and they keep archives of older content, as well. If not, it's a free forum overseen by people dedicated to a labor of love much as Arelith is, and it isn't impossible that you might just get an answer from the authority author in the field of your question.

Candlekeep has tons and tons of great stuff and material, and not all of it is even stored on the forum. Would also recommend giving this place a visit some time.

I wanna second the usefulness of the candlekeep forums. Between general research into mythologies and religions, pouring over the candlekeep forums, and reading the official Grand History of the Realms by Ed Greenwood, you can infer an answer to just about any question regarding D&D.