Got to writing on tabletop rules. Will probably need quite a bit of reworking.
Stage 1: Base construction
Players start with X amount of credits and an MCV. Deploy the MCV anywhere in your starting zone, which creates your Construction Yard. The Construction Yard allows you to rebuild buildings.
Once this is up, you may place other buildings in a radius around your MCV (Or just on your side of the board to keep it simple.). From your starting funds, subtract the cost of each building when you place them. You must have the prerequisites on the tech tree before you can place a building.
Buildings are made up of production buildings, which build units, tech buildings, which provide a special global ability and access to advanced units, refineries, which harvest tiberium and convert it into credits, and power plants, which are required to use buildings.
Power plants provide power to your base, and if the current amount of power drops below the required amount, base defenses and tech building abilities shut down.
Production builds allow you to build units each turn. Each base can produce a certain amount of units per turn, provided you have the credits to pay for them.
Tech buildings provide access to advanced units and also grant each side a global ability that can be used. For example, building a Temple of NOD not only grants access to Chemical Troopers, but also allows a player to call down a nuclear strike anywhere on the map after a certain amount of time has passed.
Once players have finished placing buildings, the skirmish begins.