Learning the Web is a good primer from Mozilla on Web Technologies. It mentions a wide aspects of tools, techniques, assets and resources. I am not new into the Web but could find a lot if interesting information over there.

Design

  1. Zurb Blog

JavaScript

JavaScript, Tools and Libraries:

  1. JavaScript basics tutorial as recommended by Learn jQuery.
  2. JS async & defer
  3. Moment.js - very nice date conversion and operation library.
  4. Spin.js
  5. JavaScripting - JavaScript libraries portal.
  6. WebStorm

jQuery

  1. jQuery
  2. Learn jQuery

CSS

  1. Learn Layout - CSS layouts explained.
  2. CSS W3 Schools - CSS tutorial, a lot of editable examples.
  3. CSS color names
  4. Border Image Generator

Sass

  1. Syntactically Awesome StyleSheets
  2. Sass Reference
  3. Sass Playground - check how your CSS looks like.

Jinja

  1. Jinja

Jekyll and Others

  1. Jekyll Variables
  2. Jekyll Templates - extensions to Liquid.
  3. Wikipedia on YAML
  4. ArchLinux Wiki on Jekyll
  5. Liquid for Designers
  6. Jekyll on an Ubuntu
  7. Adding Disqus to Jekyll

HTML

Tools

  1. Choosing a Build Tool
  2. JSHint
  3. Grunt is not Weird and Hard
  4. Gulp for Beginners

Fonts and Graphics

  1. Font Awesome
  2. Google Fonts
  3. dafont.com
  4. Unsplash - beautiful, free photos

Others

  1. Smashing Magazine
  2. Front-end-Developer-Interview-Questions