This repo shows how to set up the Node JS SDK for Zoho CRM using a self client. You might want to watch this video to help you understand the process: http://youtu.be/7AgEkotjpgQ?hd=1
It's designed to complement the docs: https://www.zoho.com/crm/developer/docs/server-side-sdks/node-js.html
The use case for this repo is when you are building an internal tool that will send/access data for your own CRM.