Getting started with the Arduino

The best way is to get your Arduino Duemilanove ready and work your way through the starting instructions on this page http://arduino.cc/en/Guide/Windows

By the end of week 1 you should be able to run blink

 /*
  Blink
 
 Turns on an LED on for one second, then off for one second, repeatedly.
 
 The circuit:
 * LED connected from digital pin 13 to ground.
 
 * Note: On most Arduino boards, there is already an LED on the board
 connected to pin 13, so you don't need any extra components for this example.
 
 
 Created 1 June 2005
 By David Cuartielles
 
 http://arduino.cc/en/Tutorial/Blink
 
 based on an orginal by H. Barragan for the Wiring i/o board
 
 */

 int ledPin =  13;    // LED connected to digital pin 13

 // The setup() method runs once, when the sketch starts

 void setup()   {               
  // initialize the digital pin as an output:
  pinMode(ledPin, OUTPUT);    
}

 // the loop() method runs over and over again,
// as long as the Arduino has power

 void loop()                    
{
  digitalWrite(ledPin, HIGH);   // set the LED on
  delay(1000);                  // wait for a second
  digitalWrite(ledPin, LOW);    // set the LED off
  delay(1000);                  // wait for a second
}

The first practical is a led-based one so there will be some extensions of this program.