This W3C HTML Tutorial provides many examples and quizzes to learn html.
This basic HTML tutorial from html dog is designed for beginners. This tutorial links to intermediate html and css tutorials.
This HTML for beginners provides a background explaining html as well as activities to learn html.
The "simple PHP web tutorial" is a basic how to get started for PHP
W3C's PHP Tutorial provides useful tools for beginners through advanced.
CSS Basics explains how CSS works and provides different examples of how CSS can help with web layout and design.
CSS Basics Tutorial offers text based tutorials and videos on CSS.
W3C CSS tutorial explains how to make html and css work together.
Color Scheme Designer is an interactive design tool in which you can choose colors by warmth. Hexadecimal codes for the colors are provided.
Color Combos provides color combinations for your website with hexadecimal codes.
Color Rotate is a 3D interactive tool that provides color schemes.
You can learn from the bad as well as the good--take a look at WebPages that Suck to learn what doesn't work in web design.
Use it.com by Jakob Nielsen, an expert in usability.