Activating this trainer:
Press F1 at main menu.
Listen for 'Trainer Activated'.
Press desired hotkey. All hotkeys can be changed on the trainer.
Numpad 1: Instant Buildings
Numpad 2: Buildings Cost Nothing
Numpad 3: Unlimited Happiness
Numpad 4: Mega Gold
Numpad 1: Instant Buildings - toggle this on after you have placed your castle, and when you build things, they are instantly completed.
Numpad 2: Buildings Cost Nothing - toggle this on, and then when you mouse over buildings and items to build, they will cost no materials and will be available to place.
Numpad 3: Unlimited Happiness - toggle on and the happiness value will only climb to 100% and never go down.
Numpad 4: Mega Gold - toggle on and you have plenty of gold. Works best to place a Treasure Room first.
Unlock more trainer options including updates from here - Kingdoms and Castles Trainer