Front-end Developers Handbook 2019
Cody Lindley, Frontend Masters
https://frontendmasters.com/books/front-end-handbook/2018/
33 Concepts Every JavaScript Developer Should Know
Leonardo Maldonado (leonardomso), GitHub
https://github.com/leonardomso/33-js-concepts
Traversing the DOM with JavaScript
Zell Liew, zellwk.com
https://zellwk.com/blog/dom-traversals/
Learning Patterns
Lydia Hallie, Addy Osmani
https://www.patterns.dev/
Book which can also be read on their website.