Ethan Marcotte, who is credited for start of responsive web design, breaks down the thinking and process behind the concept.
A nice overview of the importance of responsive design with an introduction to fluid grids and media queries.
Learn the key features of a responsive web design: Flexible Grid, Flexible Images, Media Queries
Learn the basic logic of responsive design and media queries in 3 easy steps.
Explains how to create a cross-browser responsive design with HTML5 & CSS3 media queries.
This tutorial shows the conversion of an existing WordPress theme design to a responsive layout.
Teaches how to create a minimalist style web template that is responsive from desktop size down to mobile size.
Code a simple but effective responsive navigation menu that can be easily modified and reused for future projects.
Learn how to apply responsive design principles to data tables.
Shows how to make embedded videos elastic with a simple CSS trick.
Bonus: Free Responsive Frameworks & Boilerplates
Hopefully after reading these detailed tutorials you now have a good understanding of responsive web design and how to implement it. When developing a website, a stable and scalable foundation to build on is absolutely crucial for the now, and the future. Here are a few frameworks and boilerplates to help jump-start your responsive strategies.
Less Framework 4 - An adaptive CSS grid system.
1140 CSS Grid - Fluid down to mobile.
Skeleton - A Beautiful Boilerplate for Responsive, Mobile-Friendly Development.