Good resource for mastering javascript:
http://daihuws.me.uk/mastering-javascript-useful-resources/

Mastering JavaScript: Some Useful Resources |

Of all the forms of code that a web developer has to understand, JavaScript is by far the strangest and most idiosyncratic. Part of this is a function of the process by which it came to be: rushed out by Netscape as a scripting language for their Netscape Navigator browser, it was to be adopted …