This is the loading screen you see when you zone into the battle ... or when you die.
Baradin Hold is found at the center of the map. This is where defenders resurrect.
The central tower of Baradin Hold is where defending players currently resurrect during the battle.
This bridge leads to the Slagworks from the East Spire.
Warden's Vigil can be found on the Southwestern part of the island.
Once you've managed to achieve a certain rank, much like Wintergrasp, you can pilot a tank that looks like Flame Leviathan.
North of Tol Barad is an island with mobs and bases for the Alliance and Horde. This is likely the quest hub.
Level 85 Alliance patrol the island when it's under Alliance control.