d20pro gives you complete control over your game maps. You can hide or reveal areas, move players between maps, and even move creatures to a holding area for later use.
As you make changes to a map, like altering Fog of War or moving to another map, d20pro does not automatically broadcast to your players. Information is held for a moment until you hit the Broadcast button (F5) or until units move. Part of the reason is so that if you make a mistake with a Fog or war tool or something, you can quickly correct it before you send the players the information. Broadcasting is a way to force d20pro to share your current creature and map changes with the players. If the players aren't seeing something you have changed, try Broadcasting.
The fog of war is pretty straightforward. While the you see a shaded region, players see only black. You can use the fog of war tools to quickly reveal or obscure parts of the map. The dynamic visibility setting (see creatures below) works with the fog of war do dynamically hide and reveal creatures. Remember to broadcast changes you make to the fog of war! Fog of war settings and areas are saved with the map, so it's a good idea to enable fog of war on all of your maps. That way, players don't see the map details when you open the map.