Ideally get an Arduino UNO to follow along, but there are many alternatives and most work very similarly.
To actually buy your arduino and additional components in the Gauteng area I recommend Micro Robotics or Communica. Those outside of South Africa should probably look at sparkfun for ordering.
Download the software
From arduino.cc get the arduino software package. I recommend getting version 1.5 or newer. Unzip it when it is done.
Connect it with an usb cable, you probably have to use the square/mini/micro usb cable, whatever your arduino needs. The UNO takes the