For additional learning with JavaScript, I suggest you check out some of the following resources:
Mozilla Developer Network at https://developer.mozilla.org/en-US/docs/Web/JavaScript
Secrets of the JavaScript Ninja, John Resig, Bear Bibeault, Manning
Learning JavaScript Design Patterns, Addy Osmani, O'Reilly
JavaScript: The Good Parts, Douglas Crockford, O'Reilly
The Node API online documentation is going to be your best bet to fully understanding everything that's available within the Node core set of modules. The Node API docs can be found at http://nodejs.org/api.
Additionally, there is a great website that teaches Node using actual programming problems that you must solve. The emphasis with these exercises is to understand the nuts and bolts of how Node works and get down into the fundamentals of working with streams, asynchronous I/O, promises, and more. Node School can be found at http://nodeschool.io.
Finally, the creators of MongoDB offer an amazing 7-8 week...