World Wide Web Consortium

W3Schools.com

A collection of free HTML, CSS, JavaScript, DHTML, XML, XHTML, WAP, ASP, SQL tutorials with lots of working examples and source code. Leading the Web to its full potential

Yale Style Guide - Table of Contents
Basic Design Principles

Webmonkey
The Web Developer's Resource

HTML Code Tutorial
The Idocs guide to HTML

Webopedia
Online Dictionary of Computer and Internet Terminology

Spider Food
Search Engine Optimisation and Website Promotion