Free resources are more common nowadays, and in terms of NodeJS learning resources, there are quite a bit out there. Though it’s really great when you find a course that is free and also very well structured and presented.
JSMates has released a free text-based course on NodeJS Rest API.
It is mainly for backend beginners, or frontend developers who wish to dive deeper in the realm of Full Stack.
It is broken down into small and digestible chunks with easy to follow examples, taking you progressively through each step to build a basic API and fundamentally understand how it all works.
It is now available on their blog JSMates.com