Having conducted over 100 interviews for JS positions, here is my advice.
- You have to start with ECMA5. 95% of new features in later versions can be transpiled back to it, and examining resulting code is usually the easiest way to comprehend them. Oh, how many candidates I've seen that talk about 'modern classes' with a flare and then can't explain prototypical inheritance at all. So, the best start is "JavaScript: The Definitive Guide, 6th Edition".
- Be very careful about what you read online. Blog platforms are full of script kiddies trying to feed you their misconceptions without a second thought. I generally only 'trust' two sources - Mozilla Developer Network and http://2ality.com/ by Axel Rauschmayer (I believe his books are mentioned in other answers too).
- Whenever you are faced with a particular library/technology - look from books/posts from their creators or someone associated with them.
- You have to start with ECMA5. 95% of new features in later versions can be transpiled back to it, and examining resulting code is usually the easiest way to comprehend them. Oh, how many candidates I've seen that talk about 'modern classes' with a flare and then can't explain prototypical inheritance at all. So, the best start is "JavaScript: The Definitive Guide, 6th Edition".
- Be very careful about what you read online. Blog platforms are full of script kiddies trying to feed you their misconceptions without a second thought. I generally only 'trust' two sources - Mozilla Developer Network and http://2ality.com/ by Axel Rauschmayer (I believe his books are mentioned in other answers too).
- Whenever you are faced with a particular library/technology - look from books/posts from their creators or someone associated with them.