See? I’ve kept my word to you. Here is a compilation of resources—more in-depth information than could be covered in the main part of this book—that will provide food for thought and advanced techniques. Enjoy!
Chapter 1: Investigating the Scene of the Crime
Having a shallow foundation in web design and development is acceptable, but possessing a deeper knowledge of the languages, properties, and browser support thereof can really help you understand the source of problems down the line, and may even help to prevent them.
Differences between HTML & XHTML
If you want to delve further into the differences between HTML and XHTML, these pages will lend great history, comparisons, and opinions on which one to use.