W3Schools - W3Schools is a web developers information website, with tutorials and references on web development...
Web4College - Web4College is a unique website that includes the web development tutorials and takes the design of a website to the next level. In this website, every topic is dealt with the basic concepts, detailed study, examples, and implementations.
CSS Reference - Sleek and comprehensive online reference for CSS
Free Code Camp - Learn to code by helping nonprofits.
Awwwards - Awwards focuses on web design and has an awards system that highlights exceptional design.
A List Apart - A List Apart is a fantastic blog that recently released version 5.0 which brought a great new design. A List Apart explores the design, development, and meaning of web content, with a special focus on web standards and best practices.