To put it simply, you're going to help create a world, then create/empower factions, and then throw them into conflicts. To start, everyone claims a region:
http://i273.photobucket.com/albums/jj222/ande012/protomap.jpg
Simply claim a region, and I have already claimed the north.. You'll describe it in your first IC post: its climate, its geography, landmarks, etc. We're just going to assume this world is very similar to Earth in terms of wildlife and day-night cycles. Once everyone claims a region we start creating Power Factions.

Now a Power Faction can be a lot of things. It can be a tribe, a civilization, a powerful hero or creature, a disease, a religion, a guild, an idea, and much more. You're going to start off with 5i (i=Influence). It costs 2i to create a Power Faction. Power Factions will begin with 2p (p=Power). You may spend an additional 1i to increase that power to 4, and another 1i to increase it to 5. It can no longer be increased like this ever again, so make your mind up. Greece, Troy, the Black Plague, Egyptian Polytheism, Hercules, a Dragon, the Templars - these are all examples of Power Factions.

After everyone is satisfied with Power Factions, we will take turns throwing them into conflicts. All you do is choose two or more factions to throw into conflict with each other. Perhaps a disease is affecting a tribe, four civilizations wage war, a religion begins to cure a disease, a hero defeats a great beast, etc. Some of these Factions may be allied with each other, so be sure to explain that in the OOC. Everyone then PM's me which side they favor. I tally the votes, then add them to the faction's Power rating. Whichever faction scores the highest wins. The conflict-causer will then write about the conflict in the IC and then the next person goes. The losing faction(s) loses a power, while the winning faction(s) gains a power. When a faction hits 0 power they are eliminated.

After a series of conflicts, we will name this Epoch appropriately, advance to the next Epoch, and create more Factions. As an Epoch advances, I will determine the average power rating of the current factions. Any faction with a power rating higher than the average will receive +1 power.

An interesting thing to do would be to stop, zoom in on a conflict, and roleplay in the world for a little bit.

[u][b]Encyclopedia[/b][/u]
[b]Regions[/b]
[b]Civilizations/Tribes[/b]
[b]Important People[/b]
[b]Legendary Monsters/Creatures[/b]
[b]Religions and Ideas[/b]
[b]Diseases[/b]
Other