The W3C web site http://www.w3.org has links to many of the web standards, including HTML 4.01 (http://www.w3.org/TR/html4/), Cascading Style Sheets, XML, and XHTML. The HTML validator?which is linked into the bottom of each of the pages of the online winestore?can be found at http://validator.w3.org.
The HTML Writer's Guild (HWG) is an organization that provides many useful resources to web developers, including links to lists of browser features and HTML validators. Trial membership is free for the first year. The HWG web site is http://www.hwg.org.
HTML and XHTML: The Definitive Guide, C. Musciano and B. Kennedy (O'Reilly). This book is a comprehensive guide to writing HTML web pages. It covers HTML 4 features, including Cascading Style Sheets.
Cascading Style Sheets: The Definitive Guide, E. A. Meyer (O'Reilly). Besides presenting the CSS material with many examples and case studies, this book provides a CSS support chart that shows which browsers support which features.
The original cookie specification was developed by Netscape and can be found at http://www.netscape.com/newsref/std/cookie_spec.html.