I haven't read through more than the ToC at the moment -- but here's a quick summary of what I'd be interested to see, aside from just putting together uncluttered (and as-semantic-as-possible) HTML and maintainable CSS:<p>Support for older browsers -- I'd assume anything here will support evergreen browsers (including current IE) and emphasize how to always support that baseline. But what's involved in supporting older versions of IE, in particular? Easy mode: IE9+. Hard mode: IE6+. (I haven't had business reasons to support anything older than that, fortunately). There's obviously work involved (and not all sites need to do it) but it's worth pointing in the right direction for those who need to know.<p>Support for devices: how will it display on a phone? Tablet? What's likely to break? What main approaches are there? E.g., horiz elements wrap to vertical, different display entirely, let the user zoom/scan around, etc..<p>i18n/l10n: when you add multi-language support, some text will suddenly be three times as long, or even need to be displayed right-to-left. Numbers may align differently. What will happen to your menus, dropdowns, titles, etc.? Will they wrap in an ugly way, or be cut off? It's pretty common for things to just break, because the original site was built by someone who assumed "Home" would always be 4 chars.<p>And accessibility (already mentioned in another comment). Going into depth may be overkill, but I'd strongly advise covering the choices that <i>ruin</i> accessibility entirely. There are basic best practices that aren't too hard to follow that will make a site at least usable by people with non-standard browsers (even if it won't win any awards).