I'm not going to take credit for this, these were on the message boards. Just like in most games like Age of Empires, Starcraft, etc that are similar to this in a few ways you hit Enter/Return to open up the chat box. In the chat box you put in the following messages:

moneyfornothing - this will give you 9999 gold and all types of mana
borntorun - every leader that you control gets 100% of their moves replenished
herecomesthesun - reveals entire world map
anotherbrickinthewall - allows you to build another building after you already did
stairwaytoheaven - hero gains a level (up til their max for that mission), all others in the party will level up once (until they reach level 232), and the hero can be exported afterwards.

All the ones above have been tested by me and they all work. The ones that follow are ones I never tested.

wearethechampions - wins the current mission
loser - losses the current mission
paintitblack - hides the entire world map
givepeaceachance - peace with all races
badtothebone - war with all races
cometogether - treatied witha ll races