Nodevember Videos has interesting session on ES6 (ECMAScript 6 spec discussion), this is learning about the future. https://www.youtube.com/watch?v=Hjkc9m9vYCU
JS Design Pattern book (I refer to it quite regularly) - http://addyosmani.com/resources/essentialjsdesignpatterns/bo...
Eloquent Javascript (First book I read after working for few months on JS) - http://eloquentjavascript.net/
Additionally - read the specification always helps - this is the draft of ES6 (http://www.ecma-international.org/publications/files/ECMA-ST...)
Also, if you want to learn pure JAVASCRIPT, I presume you should also work on NODE.JS because JAVASCRIPT has evolved big time in the past few years to become "THE" Language.
Recent conference (NODEVEMBER) has lot of interesting videos - https://www.youtube.com/channel/UC7z0nOE8ITfrGnXJgNzYaEQ