During game play press 'Enter' to bring up the console to enter the codes. Type in the following codes to get the corresponding effect.

Enable Mission Select:
Ophelia

Instant Win:
There is no cow level

Instant Loss:
Game over man

Enemy can't Use Psionics:
Noglues

Build Anything:
Modify the phase variance

Faster Building:
Operation cwal

Free Unit Spells/Abilities:
The gathering

Free Upgrades:
Something for nothing

Invincible Units:
Power overwhelming

No Fog of War:
War aint what it used to be

No Supply Limit:
Food for thought

Unlock 10,000 Minerals and Gas:
Show me the money

Unlock 500 Crystals:
Whats mine is mine

Unlock 500 Vespene Gas:
Breathe deep

Continue Playing after Win:
Staying alive

Reveal Entire Map:
Black sheep wall

Skip Terran Level:
Terran# (Replace # with number of mission).

Skip Protoss Level:
Protoss# (Replace # with number of mission).

Skip Zerg Level:
Zerg# (Replace # with number of mission).