The very first thing to do is to select the arduino board which suits the requirement. Visit the website of arduino where one can get all the details about the arduino boards and arduino softwares. Beginners are recommended to use arduino duemilanove board or arduino uno board. Those who are used to with handling the hardware things, soldering etc. can choose arduino pro-mini board. All the details of the available arduino boards can be found from the arduino website itself. This article and the following ones are explained based on the arduino pro-mini board and the IDE version 1.0.3 for windows. The advantage of this board is that it comes in very small in size; bread board compatible burg stick connectors can be soldered according to our requirements. It is very breadboard friendly and occupies very less space of a typical breadboard.
Fig. 2: Typical Arduino Pro-Mini Board
Refer to the code and circuit for blinking an external LED connected to the pin number 5 of the arduino board.