I've been noticing that a lot of people (not people on instructables, but people interested in electronics in general) don't really know about LED's. No one in my science class at school had ever even heard of them. This is an easy introduction to LED's that should teach you the basics. It's good if you're interested but have no idea where to start. I also thought this would help out anyone wanting to enter the contest, but it took me a while to finish.
Remember, (As always) feedback and ratings (positive or negative) are always appreciated!
FOR MORE INFORMATION SPECIFIC TO WIRING, YOU CAN SEE NOAHW'S INSTRUCTABLE "LEDs FOR BEGINNERS"
Step 1: Name/Background Info
LED is an acronym for Light Emitting Diode. Well, you ask, what on earth is a diode.
A diode is a device that, in simplest terms, allows electricity to flow through one way but not the other. Those of you who are knowledgeable about mechanical things could think of it as sort of a check valve. If you have no mechanical knowledge, disregard that last sentence.
Now that you know what a diode is, an LED is just one that emitts light (But you could probably figure that out just from reading the name).
Step 2: More Important Information
Anode - The p-side which is the longer leg. And the...
Cathode - Which is the n-side and shorter leg.
Since you know these terms you can remember that electricity flows easily from the anode to the cathode but not the other way around.