Ref: http://arduino-info.wikispaces.com/ArduinoPower

<code>
/* YourDuino Example: Relay Control 1.10
  Handles "Relay is active-low" to assure
  no relay activation from reset until
  application is ready.
   terry@yourduino.com */

/*-----( Import needed libraries )-----*/
/*-----( Declare Constants )-----*/
#define RELAY_ON 0
#define RELAY_OFF 1
/*-----( Declare objects )-----*/
/*-----( Declare Variables )-----*/
#define Relay_1  2  // Arduino Digital I/O pin number
#define Relay_2  3
#define Relay_3  4
#define Relay_4  5

void setup()   /****** SETUP: RUNS ONCE ******/
{
//-------( Initialize Pins so relays are inactive at reset)----
  digitalWrite(Relay_1, RELAY_OFF);
  digitalWrite(Relay_2, RELAY_OFF);
  digitalWrite(Relay_3, RELAY_OFF);
  digitalWrite(Relay_4, RELAY_OFF);  
  
//---( THEN set pins as outputs )----  
  pinMode(Relay_1, OUTPUT);   
  pinMode(Relay_2, OUTPUT);  
  pinMode(Relay_3, OUTPUT);  
  pinMode(Relay_4, OUTPUT);    
  delay(4000); //Check that all relays are inactive at Reset

}//--(end setup )---


void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
//---( Turn all 4 relays ON in sequence)---
  digitalWrite(Relay_1, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_2, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second  
  digitalWrite(Relay_3, RELAY_ON);// set the Relay ON
  delay(1000);              // wait for a second
  digitalWrite(Relay_4, RELAY_ON);// set the Relay ON
  delay(4000);              // wait see all relays ON
  
//---( Turn all 4 relays OFF in sequence)---  
  digitalWrite(Relay_1, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_2, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second  
  digitalWrite(Relay_3, RELAY_OFF);// set the Relay OFF
  delay(1000);              // wait for a second
  digitalWrite(Relay_4, RELAY_OFF);// set the Relay OFF
  delay(4000);              // wait see all relays OFF  
  

}//--(end main loop )---



//*********( THE END )***********
</code>

Howto fade a motor or LED

<code>
/* YourDuino PWM Power Example
 "analogWrite" outputs a Pulse Width Modulated signal
 terry@yourduino.com
 Fades an LED or Lamp up and down
 NOTE: analogWrite values are from 0..255
 
 */

/*-----( Import needed libraries )-----*/
/*-----( Declare Constants )-----*/
#define ledPin  9    // LED connected to digital pin 9
/*-----( Declare objects )-----*/
/*-----( Declare Variables )-----*/
int fadeValue;  //Value to be sent to PWM


void setup()   /****** SETUP: RUNS ONCE ******/
{
  // (Not Used)

}//--(end setup )---


void loop()   /****** LOOP: RUNS CONSTANTLY ******/
{
  // fade up min to max 
  for(fadeValue = 0 ; fadeValue <= 255; fadeValue +=5)
  { 
    analogWrite(ledPin, fadeValue);  
    delay(50);                            
  } // End Fade Up

  delay(2000); // Hold 2 seconds at max brightness

  // fade out max to min
  for(fadeValue = 255 ; fadeValue >= 0; fadeValue -=5) 
  { 
    analogWrite(ledPin, fadeValue);            
    delay(50);                            
  } 
  delay(2000); // Hold 2 seconds at off

}//--(end main loop )---

/*-----( Declare User-written Functions )-----*/
//None

//*********( THE END )***********
</code>