Step 1: Power intake
LEDs are wiered about there power intake. Most LEDs require about 3 volts any more, and they burn out and smell bad. any less, and they dont light up good. I know what you are thinking you can use a 1.5v battery such as a AA or AAA if you have a Joule Theif, but that is another instructable. As of amperage, LEDs very greatly across a wide spectrum of highs and lows, but 20mA is standard.