Create a shortcut to the ''CoDSP.exe'' file located in the Call Of Duty program files. Right click on the shortcut and go to properties. Go to where it says ''Target'' and add the following onto the end of the existing link:
+set thereisacow 1337 +set developer 1 +set sv_cheats 1 +set monkeytoy 0

So the link should now say something like:
''C:Program FilesCall of DutyCoDSP.exe'' +set thereisacow 1337 +set developer 1 +set sv_cheats 1 +set monkeytoy 0

Next go into the game and bring down the console by pushing the button above ''TAB'', then enter the code from below for the desired effect.

Now start the game. Press the tilde (~) key to open the console, and then enter the following:

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
testgun - ?
cvarlist - Gives a list of all cvars in the game
cvardump - Dumps all cvars to the console
cvar_restart - Reset all cvars
cmdlist - Gives a list of all commands in the game
shaderlist - Gives a list of all the shaders on the current map
imagelist - Gives a list of all images on the current map
snd_list - Gives a list of all sounds currently being used
entitylist - Gives a list of all entities currently in use
bindlist - Gives a list of all currently bound keys
gfxinfo - Gives information about the game graphics
savegame - Saves your game
loadgame - Load your saved game
reset - Resets a variable to it's default state
cinematic - Plays a cinematic file
debug_tankall 1 - ?
chain 1 - ?
ai_nocriticalsections 1 - ?
testmodel - Spawns a model that you input
ai_corpsecount - how many seconds dead bodies remain on-screen
cg_brass 0 - Turns ejecting shells off
cg_marks 0 - Turns bullet marks off
cg_drawFPS 1 - Turns fps display on
cg_drawTimer 1 - Turns game timer on
cg_drawStatus 0 - Turns HUD off
cg_hudAlpha # - Sets HUD transparency (default is 1.0)
cg_draw2D 0 - Turns HUD and crosshair off
cg_drawCrosshair 0 - Turns crosshair off
cg_crosshairAlpha # - Sets crosshair transparency (default is 1.0)
cg_thirdPerson 1 - Turns on 3rd person view on.
cg_shellshock # - Activates the shellshock effect for the duration that you specify
cg_showMiss 1 - Shows you how far off you are from hitting an npc if you've missed.
cg_shadows 0 - Turns shadows off.
cg_skybox 0/1 - ?
cg_stats 0/1 - ?
cg_noRender 0/1 - Gameplay will continue, but will no longer be rendered.
cg_subtitles 0/1 - Turns off/on subtitles
cg_noPredict 0/1 - ?
cg_selectPlayer - ?
cg_tracerChance - ?
cg_ignore 0/1 - ?
cg_letterbox 0/1 - Turns off/on letterbox format
cl_debugMove 0/1 - Turns off/on player and AI movement debugging.
cl_run 0/1 - ?
cl_running 0/1 - ?
con_debug 0/1 - Turns off/on console debugging.
dmflags 0/1 - ?
fx_debug 0/1 - Turns off/on fx debugging.
fx_draw 0/1 - Turns off/on fx. If set to 0, no smoke, muzzle flashes or particle effects will be drawn.
fx_enable 0/1 - Turns off/on fx. If set to 0, fx will be disabled.
fx_freeze 0/1 - Turns off/on fx freezing. If set to 1, smoke - for example) will freeze in mid-air.
g_changelevel_time - ?
g_gravity # - Changes the amount of gravity in the game (default is 800)
g_spawnai 0/1 - Don't spawn on the map (usually crashes the game)
g_ai 0/1 - Turns off/on ai in the game.
g_debugDamage 1 - View the amount of health that an npc has and how much damage you have done to it.
g_vehicleDebug 0/1 - Turns off/on vehicle debug mode.
g_debugMove 1 - Turns off/on player and AI movement debugging.
g_debugBullets 1 - Turns off/on bullet debugging.
g_debugShowHit 1 - Turns off/on hit debugging.
g_drawEntBBoxes 1 - Turns off/on entity bounding boxes.
g_gameSkill # - Sets the game skill level
g_knockback # - Sets the knockback power of weapons (default is 1000)
r_fog 0/1 - Turns off/on fog
r_drawEntities 0/1 - Turns off/on objects and npc's. Default is 1
r_drawWorld 0/1 - Turns off/on all objects and backgrounds. Default is 1
r_showtris 0/1 - Turns off/on wireframe mode. Default is 0

Note: If the console tells you that "sv_cheats are read only" after you enter a code, then try typing "setrandom sv_cheats 1".