innocent_man did a great write up on Requiem that's sadly on geocities. Take a look!
The white-wolf.com wiki entry for VtR is pretty handy, especially the section on Clans and Covenants. In particular, there are five main sects of vampires, and unlike the old Camarilla and Sabbat, they tend to coexist much more closely, which leads to all kinds of intrigues and nasty, nasty shit.
And now, a very quick rundown on what's going on in my setting, Austin, TX:
Austin is a city that's undergone tremendous change and continues to change every day. One of the main themes of this chronicle is vampires (and people) reacting to a world that's racing past them. How people react to change, or try to hold on to the status quo, even if it's a status quo they helped build when they were revolutionaries.
The Carthians are easily the dominant power in the city. Several Carthians moved to Austin in 1971, and in a largely bloodless coup took control of the Primogen council and by extent the city itself. A weakened and frustrated Invictus Seneschal holds very, very little power. Her sire the Prince fell in to Torpor in the 1930's, and rumor has it he's set to wake soon. No one really knows what's going to happen and everyone is scrambling to consolidate power and screw over their rivals in the face of an uncertain future.
Not counting the PCs, there are about 45 Kindred in Austin. It's over populated somewhat, but the music scene, the college, and tourism all help sustain the undead population. Carthians are easily the most populous, with the Circle of Crone second in numbers and power, followed by the Invictus, the Lancea Sanctum, and a reclusive pair of Ordo Dracul.
I'll post the vamps of Austin by Covenant over the next week or two. First up, the Carthians.