WD 300 gives SBG profiles for many fiefdoms, as well as characteres to go along with several of those fiefdoms (some of which were then later re-released in a more official form). Anyways, the article gives a little background info on several of the fiefdoms.

If you're looking for more official, non-GW resources, both Encyclopedea of Arda and Tuckborough are pretty comprehensive sites. Tuckborough is more thorough about listing sources, too, so you know which books to look into if you're so inclined.