Note: This procedure involves editing a game file; create a backup copy of the file before proceeding. Use a text editor to edit a saved game file in the game folder. Find the "FOOD", "WOOD", and "GOLD" entries and change the corresponding values to "100000".
During gameplay type in a code below:
DOYOUSEE - Show map
MAKEMENAILS - Hard mode
GIMMEGIMME - Get resources
Save Game Edit
Open one of your save games with a text editor and look for the Gold, Wood & Food entries. Change their value to 100000 or whatever you want.
For lots of units you will first have to have lots and lots of food in your global stocks. First you have to pause the game by pressing the P key. You should be able to still move around and select things while the game is paused. Now select a building that can spawn units and select how many units to be trained. Now you should be able to build units beyond the limit.
In any of the missions that you find horses you can use them to scout the land and your enemy cant kill them.