Setting up LEDs in series is easy. Here are the parts you will need:

a breadboard set up for 5 volts
a 12 volt power supply
three LEDs
one 220 ohm resistor

This is a schematic of three LEDs in series with a resistor






Step One: begin with setting up one LED. Connect the long leg to 5 vols and the short leg to a 220 ohm resistor. Connect the 220 ohm resistor to ground.








Step Two: add an LED to the circuit. Connect the long leg of the new LED to the ground of the previous LED and the short leg of the new LED to the 220 ohm resistor.







Step Three: add another LED to the circuit in the same fashion as the previous LED. You have effectively daisy chained three LEDs. Note what happens when you have three leds in series, powered from 5 volts and 1 amp.