*Note: I highly recommend that you don't use cheats during any sort of game play. It makes you more of a crappier player since you wouldn't have any experience playing under normal conditions. It's more of a challenge without codes, so you become more of an aggressive player. If you're bored of playing legit, THEN, and only THEN, can you use cheats to "spice" up the action and blow some time.*

To use a cheat code, press the enter key during non-multiplayer game play, type in the code(high-lighted in yellow), and press enter again. The message "Cheat Code Enabled" should appear.
power overwhelming God mode
show me the money Gives you 10,000 vespene gas and 10,000 minerals
operation cwal Speeds construction of buildings, units, and upgrades
the gathering Gives unlimited energy to all casting units
game over man Ends your game as a loss
staying alive Prevents the mission from ending due to victory or defeat
there is no cow level Completes the current mission
whats mine is mine 500 minerals
breathe deep 500 Vespene Gas
something for nothing Gives all upgrades
black sheep wall Shows entire map
medieval man Free upgrades to units
modify the phase variance Ability to build all buildings
war aint what it used to be Disables fog of war(shroud)
food for thought Ability to build units beyond the support limit
ophelia Enter this to enable level skipping cheat. Then enter the mission you want to skip to (i.e., "terran10") to go there. For Brood War levels type x before the levels (i.e., "xterran8")

The following codecan only be used if you have Brood War and when you play as Zerg.

radio free zerg Plays a cool Zerg motivating tune