Press ] or + during gameplay to bring up the console window. 
Note: Some versions of the game may require you to press Left Ctrl and ] or Left Ctrl and + to bring up the console. 
With the console open, enter the following codes: 

Effect   -   Code 

God mode - Application:SetGodMode(1)
Cast heroes faster - Application:FastHeroCast(1)
Unlimited Mana - Application:SetNoManaUsage(1)
99999 of all resources - Application:GiveMeGoods(99999)
Fast construction - Application:SetBuildingFastBuildMode(1)
Can build advance warriors - Application:SetFigureTechTreeMode(0)
Can build any building - Application:SetBuildingTechTreeMode(0)
Freeze current time of day - Atmosphere:TimeLock(1)


Note: Change (1) with (0) or vice versa to disable the corresponding active code. 
example:
Application:GiveMeGoods(99999)

Debug Mode: Press Left Ctrl and D during gameplay to enable debug mode. Hold Left Ctrl and press W, E, R, or S to toggle various debug functions.