devdocs.io is a comprehensive web application developer reference site. You can configure it to show the references for HTML, Javascript, Node.js etc. It is HIGHLY recommended that you bookmark this site and have it open when you are coding. This is the definitive quick resource!
Tutorial and education specific resources
W3scools provide excellent interactive tutorials and references that we will use a lot in class:
There are many excellent screencasts on programming with Javascript. Just Google video serach “learn Javascript” and you will a multitude of resources. Here is one example that seems very well organized and easy to follow: Javascript Tutorial - Programming Tutorial for Beginners Pt 1