Depending on whether or not you are making MP maps, or zombie/SP/co-op maps, the answer to your question is slightly different. I dont know that much about zombie mapping, as I've only had WaW since January (I think I missed most of the problems people were having before that) and I am modding for MP so far.
Going on the assumption that you want to map for MP, basically of course you do need a .GSC file for your map (this applies also for SP/zombie/co-op mapping as well). All the stock map .GSC files are located in:
[COD:WAW INSTALL]/raw/maps/mp
Use one of those as a template for your own custom map, changing the details in it accordingly.
Also, with WaW there is a new fella in town called the .CSC file, which is the twin brother of the map .GSC - for every map .GSC file, there is a twin of it named with the .CSC file extension.
.CSC files are designed for client-side function, to keep lag down when things like FX and stuff run. You cannot run things like FX or ambient sounds without a client .CSC file, and they work in compliment with the
Both the .GSC file and the .CSC file are proprietory file types made specifically for the Call of Duty seires. The .GSC file is an acroynm of Grant Stuart Collier (hence .GSC), once CEO of Infinity Ward (now no longer), and the .CSC file appears to be an acroynm of Client Script Code.
You will find the stock MP map .CSC files in:
[COD:WAW INSTALL]/raw/clientscripts/mp
There are now plenty of tutorials dotted around the community forums on the use of the .CSC file for adding FX and sounds. A tutorial for adding FX using .GSC and .CSC files can be found here:
http://wiki.modsrepository.com/index.php/Call_of_Duty_5:_FXs_Script_Struct
And one for adding ambient sounds using .GSC and .CSC files can be found on this very site here:
http://www.modsonline.com/Tutorials-read-576.html
As for the .CSV files, the main one to compile your map into fastfile is often refered to as the "zone csv" file. This will be located in:
[COD:WAW INSTALL]/zone_source
There are other .CSV files for making different bits of a MP map, such as the one for making the loadscreen load.ff file. These aren't located in the zone_source folder, but in:
[COD:WAW INSTALL]/raw/maps
That's the location whether the map is MP or SP/zombie/co-op.
Then there is the mapsTable.csv file. This .CSV file contains info which the game uses to get info on what your minimap is called, what your loadscreen is called, and what character sets you are using for your map (sometimes called "Factions", a term from COD4). This is located (you have to create your own one - the game wont do it automatically for you) in:
[COD:WAW INSTALL]/raw/mp
You will find the stock mapsTable.csv file as an example at that location.
After you compile your map and run it for the first time from a mod folder, the game produces another .CSV file called missingassets.csv. This does what it says on the box: it gives you all the missing assets that your map needs in order to work properly.
NB: mod folders to run your map are not located in your root game install. Please make sure you have searched this forum to find out the locations of the "usermaps" directory in Windows Local Settings (slightly different directory tree depending on whether you run XP or Vista). If you attempt to use the game's root install "usermaps" and "mods" directories, the map/mod wont run.