Re: Newbie struggling with Adafruit lesson 3: RGB LED HELP!
Take the long pin and hook it up to 0V, -, or ground, and put any of the other pins on +, or 5V. If it doesn't light up any color, switch em. If it does light up on either choice, leave the long pin alone and try the other pins to see the other two colors. If you have 5V or + on the long pin, you have Common Anode. If you have 0V on the long pin you have Common Cathode. Knowing the difference is important for how you set up your breadboard. Don't forget to use the resistor.
Figure that part out then you can move on to how to wire it up.