HTML5 Doctor’s HTML5 Element Flowchart:
A visual flowchart to answer the ongoing question, “which HTML tag should wrap this content?” These simple rules will help keep code clean and easy to extend and digest by browsers and bots.
Learnlayout.com: Learn CSS Layout tutorial:
This 19 part in-browser tutorial explains in depth the core CSS principals any web developer will need to grasp. Visual examples for each property help paint a rich picture and establish a strong foundation for styling page layout.