In no particular order these external resources supplement the tutorial by providing shortcuts to commonly used information and further learning.All HTML elements
Listing of all the HTML elements that are allowed and what they do. Essential cheat sheet for remembering what does what in HTML.
List of escaped entities valid in HTML. Helpful for using unique characters or avoiding using characters used by HTML that would break your code.
Walkthrough of some of the lesser known, but very useful semantic HTML elements.
Higher level step through of some of the theories and concepts behind developing a website. Talks about topics like typography, color schemes, wire framing, information architecture, and plenty more.