what you will need...
1: arduino (I am using an Duemilanove)
10-15: jumper wires
Step 1: Adding the LED's and Resistors1
Make Sure the long lead is to the left as seen i the picture!
Next add the Resistors to the last 3 LED's,
place in the long lead.
Step 2: Wiring This to the Arduino!
Next going to each led, take 4 more led's and go from the 2 grounds to each short lead.
Step 3: Wiring the Positive Leads!
pin 13 has a built in resistor so that is why you don't need to use a resistor.
start with pin 13 and wire it to the first LED.
Then Just go do the line and wire the rest of the LED's using pins 12,11,10