Press [Alt]+21 ingame to open the console.
Then type in the following codes.

Code                  Result

yesmen              - Ai will always respond favorably to a request.
instantconstruction - buildings finish in one day.
tag XYZ             - Change to a different country in current game.
                      Replace XYZ with three-letter country code.
cash                - Gives you a lot of money.
prestige            - Gives you a lot of prestige.
goods [amount]      - Gives you an amount of goods, including money.
leadership          - Gives you officer points, you can recruit as many
                      as you want.
instantresearch     - research finish in one day.
plurality [number]  - Sets the countries plurality.