I'm planning on running a COD 4 server but I know very little. Is running a COD 4 ranked server like running a Battlefield 2 ranked server where only "chosen" resellers are allowed to host? Or is it as simple as writing something in the server config file? Any help and advice would be greatly appreciated.

No, A Ranked server, is just a stock CoD4 server, you change nothing, you install nothing,

Well, you can edit the server config file to your liking

but other than that you just leave the server the same, and its ranked

wait I'm confused lol

does activision monitor which servers have unchanged server files and list them as ranked servers or how does it work?

well its only unranked if the server is modded, like AWE, PAM, DAMN, Zombie, ACE and eXtreme... if you dont put any of them, or any kind of mod on your server, than your good.

ohhh ok now I get it

what about "modtool"? I downloaded this 600MB+ rar file from the internet and it has a bunch of stuff in it

The mod tool is used to create mods and maps.

you can get more information on it here

Modding/Mapping - Call of Duty 4 Forums