To enable Call of Duty cheats, first modify your Call of Duty shortcut (right click on it and then left click on properties) and add the following text in the target field AFTER all the other stuff:

+set thereisacow 1337 +set developer 1 +set sv_cheats 1 +set monkeytoy 0

Then start the game using that shortcut and press [~] to open the console, and type the following codes (NOTE: All the codes with 0/1 are toggles; use 0 to turn them off and 1 to turn them on):

god - God mode

give - Gives indicated item

give health - Full health

notarget - The enemies won't shoot you

noclip - You can go straigh through walls

give all - Gives all items

give ammo - Gives ammunition

debug 1 - Turns debug mode on (0 to turn it off)

developer 1 - Turns developer mode on (0 to turn it off)

ufo - Fly mode

jumptonode - Teleports you to a specific node on the map

kill - Suicide