Before you begin, make sure that you reflash the firmware to the latest on your Intel Edison board. Watch this previous Hands-on IoT episode to learn how to do that.
Because there is limited room available in the root partition of your Intel Edison, you want to install Node-RED in the home directory. Brian shows you how to do a local install to your home directory. Then, he shows you how to configure and auto-start Node-RED from this directory. Lastly, you can learn how to add the Watson IoT Platform nodes into your Node-RED installation.