Connect the red wire as follows:

• JST Connector + (or USB breakout VBUS)
• Power switch IN
• Power switch OUT (interchangeable)
• 12v Boost Converter IN
• 12v Boost Converter 12v
• Resistor in/out 
• + (anode) pad of your first letter

Connect the black wire as follows:

1. JST Connector - (or USB breakout G)
2. 12v Boost Converter G
3. - (cathode) pad of your last letter
4. Connect the rest of the letters as shown: the wire goes from the cathode of one letter to the anode of the next letter.

Follow along with the video at the beginning of this guide for a step-by-step build tutorial.