You can try going to White Wolf's websites and looking up their changling line (I suspect so called cause no WoD gamer was going to play a game called "Fairies.") I haven't seen the rulebooks, but I played in a Changling game for about a year, and it was packed with Seelie/unseelie intrigue from what I remember. I'd almost universally attribute that to game source materials, not the stroyteller as well.
A Midsummernights Dream, William Shakespeare, will also give you a fair idea about fairie courts.
The books of faerie and some of the Books of Magic by DC comics is pretty good as well.
Unfortunately, I can't think of anything actually D20 related as a resource, but all of the above should allow you to fudge it for yourself.
I'll admit I'm waiting eagerly for everyone elses replies.