Below I list tutorials from W3Schools, an excellent, no-bullshit resource for learning from the bottom up how to develop a website. They cover several fields, so I've grouped together their tutorials into areas of development in the rough chronological order that I suggest learning them.
Obviously you don't have to go literally from start to end, so I've included rough difficulty ratings so you can skip over things and return to them at a later date with more knowledge in your brain. Key: Easy Reasonable Advanced
Feel free to add more and discuss in this thread... I've copied this post from a topic I made on another forum, and I guess it might be useful as an ATF sticky or something.
Basic introductory tutorials
HTML Tutorial webpage structure, and the tags and what they do
XHTML Tutorial to standardise your HTML
CSS Tutorial to style your XHTML
Making webpages more dynamic (client-side)
AJAX Tutorial to grab data dynamically while browsing
Making webpages more dynamic with... PHP
You need to run a web server to work with PHP/SQL; see downloads at bottom.
W3C PHP Tutorial to write dynamic scripts
Making webpages more dynamic with... Ruby on Rails
You need Ruby installed on your system to run Ruby scripts; see downloads at bottom.
Ruby on Rails guides to help you build a web application
You need a MySQL server — or SQLite if you prefer — to work with a MySQL database; see downloads at bottom.
SQL Tutorial to use a database to manage content
XML Tutorial to store pure content in a standard format
RSS Tutorial (based on XML) to notify subscribers of updates
XSLT Tutorial to present your XML in a browser-readable format
PHP.net literally the best open code reference in the entire Internet
A ton of Flash tutorials
Another ton of Flash tutorials
A List Apart: articles on web design and standards not just about coding properly!
Design/web galleries and resources
CSS Zen Garden
DarkEye colour-sorted galleries
Web Developer's Handbook a massive, massive resource. Don't approach as a beginner, you'll be overwhelmed
PHP 5 for Dummies
PHP & MySQL for Dummies
Mastering Regular Expressions - it's important to know how to use regex properly if you're doing complex stuff in processing, but consider this super-advanced!
PHP server for Windows [WAMP]
PHP server for Windows and other platforms [XAMPP]
MySQL server (standalone)
Ruby and Ruby on Rails