A 
quadcopter, also called a quadrotor helicopter or quadrotor, is basically a multi-blade helicopter that is lifted and propelled by four rotors. Quadcopters are classified as rotorcraft, as opposed to fixed-wing aircraft, because their lift is generated by a set of vertically oriented propellers.
Quadcopters generally use two pairs of identical fixed pitched propellers; two clockwise (CW) and two counterclockwise (CCW) se. These use independent variation of the speed of each rotor to achieve control. By changing the speed of each rotor it is possible to specifically generate a desired total thrust; to locate for the centre of thrust both laterally and longitudinally; and to create a desired total torque, or turning force.
Quadcopters are not new. There are several models on sale from various vendors.
Sizes range from tiny machines that can fit into a man's pocket to full-sized models able to lift a full grown man.
These are either flown for fun or used to make aerial photography.
Building a quadcopter on your own is quite an interesting project and requires a lot of work. Basic soldering skills is an advantage.
I can tell since I have made several models.
Basically you would need the following:
Frame (Different sizes available)
Motors (Different sizes here too)
Propellers
ESCs
Battery
Transmitter
Receiver
Battery charger
The idea of this thread is to guide and provide support to interested persons from parts acquisition through to the actually working model.
Hopefully, we can get some machines to fly and have lots of fun in the process.