Help with adding maps to server

Hi all,
I have just found your site and it looks great… now on with my question…. I am a newbie so all the help I get I need very much…. I have just started a COD2 clan, which we have a game server and website…. What I would like to do is add a custom map to the game server but I am now sure how to do that….. I think you have to add the files to the website ftp so that the download will be faster but I am not sure….. So if someone knows about this please help this newbie out…LOL…..
Thanks
bama