With all the devices available to view websites, in all different sizes and shapes, the need to incorporate responsive design features on a website is greater than ever. Here are some excellent resources to aid in the development of responsive designs.
This article from A List Apart is the introductory article about the approach of responsive design.
Learn how to use CSS3 to add expressions to media type to check for certain conditions and apply different stylesheets with this article from Web Designer Wall.
Read this before setting out to create your first responsive design website. The points raised in this article will guide you to be careful about the choices you make in your design.
The FlexSlider plugin is a fully responsive jQuery slider plugin, ideal for use on a responsive website. Incorporate it into your WordPress website using my Style My Gallery plugin which will be launched in the new year.