Plug one end of a standard microphone cable into the microphone, and one end into the input of the mixer or microphone preamp. Many mixers and almost all microphone preamps are equipped with 48 volt "phantom" power for compatibility with condenser mics. If you are not sure if your mixer or preamp has phantom power, consult your owners manual for details.
Plug one end of a second microphone cable into the mixer or preamp's output, and into the power amplifier, speakers or recording device (depending on your particular use and equipment layout). If you are using a computer audio interface, many of these units double as a preamplifier and phantom power source for condenser microphones, and are connected to the computer with a USB or Firewire cable from the interface's output. Consult the interface owner's manual for proper computer connection.
Turn on the preamplifier or mixer, and press the switch to activate the phantom power. Your condenser microphone is now ready for use.