files are to be extracted into the "mp" folder of S.T.A.L.K.E.R.: Clear Sky root directory (for instance "C:\Program Files\STALKER_Clear_Sky\mp"). Then you can play on the new map. Note: If you are creating the server, make sure you reboot your computer after extracting the map files.
Tom's original mappack is rather heavy (75Mbs), so now you can pick only this medium sized .jpg with pixel dimensions of 2085x5407. Download Tom's original mappack if you like to have even larger version of this :) This is just plain map, no places etc. named in it. Bloody great map!