Nicole provides a step-by-step explanation of why it will probably benefit you to add classes to your headings to ensure consistent styling without writing overly-verbose CSS.
A brave attempt to explain the new outline algorithm in HTML (although it inaccurately states that no browsers have support for it—Firefox shipped with it a while back).
You can safely skip the comments: most of them are discouraging, ignorant, and frankly, just plain stupid.
A handy little tool for quickly generating ratios (like the golden section) from a number.
A great post from the frontline of markup. This is just a taste of the confusion to come.
Bruce gives a good explanation of the difference between section and article in HTML5.