If you installed the mod correctly, then your default maps should appear in the map list, ie. boot_camp, crossfire etc... If they aren't showing up, try going into the console, and type map "crossfire" or any other map, and if it says error map not found, or something like that, you may have installed the mod wrong. This is a seperate mod, so it should go in your c: \..\Half-Life directory, not c: \..\Half-Life\esforces directory, hopefully you didn't do that...