LEDs con be confusing sometimes so I decided to make a guide on using them. If you have any Questions about LEDs that werent answered in this instructable, Please feel free to comment or question.

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.

Step 2: Annode or Cathode?

Another thing LEDs are wierd about is their positive (+) and negitive (-) legs. LED stands for Light Emitting Diode. Since a diode makes power go one way, It has to be on the right way for it to work. there are a few tricks to finding what is the annode (+) and what is the cathode (-).
ne is that the Cathode is shorter than the annode. the other is that the side with the cathode has a flat spot on it. Using these tricks will help you not mess up you LED related circut.

Step 3: Many Colors

LEDs cme in many sizes shapes and colors. this makes them extremely versitile. ther are alot of exotic LED colors but here are alot of the standard ones.
RED
YELLOW
GREEN
AMBER
WHITE
BLUE
There are also:
Blinking LEDs
RGB LEDs
A lot more

Step 4: Connections

There are 2 ways to wire LEDs together. One is to wire them Annode to Annode Cathode to Cathode that will run on the same voltage but more amperage. the other is to wire them annode to cathode annode to cathode. That will have a higher Voltage but a lower amperage.

Step 5: Update: Resistors.

Update:
Due to popular community request, I have added a section about resistors and ohm's law.
First, resistors. Resistors are small electronic devices that limit current and/or voltage. (hence the name resistor) In "power sorce" I put a big, fat X over the 9v battery. That was wrong-ish. You can use a 9v IF and only if you have a resistor. "But what resistor should I use?" is a qestion I can hear through you computers. You have to use "Ohm's Law". Ohm's Law is a mathematical formula used to find resistence, voltage, or amperage. (it can also determen wattage, but that is a little complicated.) It states: R=V/A where "R" is resistance, "V" is voltage, and "A" is amerage. Using that, you will be able to find the proper resistor to use with you LED. (You have to do the math on your own, that way you learn)

Step 6: End

hope this helped you enter the wonderful world of LED projects. I am open to any and all comments and/or requests. I'm not promising that I will put it up, but I am open to you ideas.

- Techturtle2