All the necessary files are found within the .bsp file. All you need to do to ready the map for play in your game is to extract the .bsp map file into the map folder of whatever game you intend to play it in. The materials folder is optional and is there to supply a thumbnail preview for Garry's Mod users.

Example map install location:
C:\Program Files\Steam\SteamApps\"YOUR USER NAME"\garrysmod\garrysmod\maps

Created by Jack "Serge" Murphy, with remix by DJ Pretzel.
Enjoy!