Well, I haven't seen a thread for this yet, so I think this would help many people. Even if most people have seen this, this will still serve as a common, easy to access guide to using the console in CoD4 Single player. For multi-player, you cannot force yourself as host, unlike MW2. Thereupon, I have no idea how to use it for MP, since I do not host servers.
1. Enable Console. Go to option>game options>enable console.
2. press "~" and enter the following code without quotes; "seta thereisacow 1337"
3. then enter the following code for maps.
spdevmap(space)(name of map)
(map names can be found in Program Files>Activision>Call of Duty 4 - Modern Warfare>zone>english)
examples include "spdevmap bog_a", "spdevmap bog_b", and more.
Note: this should load the map. you do not to do this in the future for any other maps.
jump_height (add number here, 1-1000)
timescale (add number. 2 is 2X normal speed, etc.)
give (name of weapon. may need to experiment and toy around)
cg_fov (add number. decides your field of vision)
player_sprintspeedscale (2 = run 2X faster) Note: input player_sprint, and the auto-finder will list several results. some will edit how long you can run, how fast, how much time to recharge, etc.
"cg", "player_" and "r" are common starters.
Note: sometimes you can find them by yourself. if you input intel, it will show you the matches that resemble it.(basically like google's suggested searches before you finish typing).