I started learning Node.js since 2011 by writing several small scripts. Because I've worked at both back-end and front-end sides several years early so Node.js was not very difficult for me at that time. But, without real project, everything was just for fun.
The first project I've done with Node.js is upgrade a chat application, replace the traditional AJAX-pull mechanism with a modern server-push mechanism. I got a copy of "The Node Beginner Book" by Manuel Kiessling, and done some researches about Socket.io, that's it. It taken around 1 week to get the project done. Today, we may do the same thing in a hour :)
I did not follow any Node.js class.