Slashback Software

 w3schools.com explains how things work with try it yourself examples.

quirksmode.org explains why things don't work in your browser.

Another site you might like is Jakob Nielsen's useit.com.  It has a lot of advice focused on usability.  I like this bit:

Jakob's Law of the Web User Experience states that "users spend most of their time on other websites."

The point being that if you make a really nifty design with really cool effects, but visitors can't find the scroll bar or tell if something is a link or not, they won't stick around.  You may have really impressed them, but not the way you intended...

When I search google and find myself on the same page... again... I'm putting a link here!

Add and Remove Elements with JavaScript (reprise)  Thank you Dustin Diaz!

Regular Expression Quick Start from regular-expressions.info.

A gold mine of articles from Mitchell Harper at Dev Articles.  Hasn't been updated for a while, but the information is just as true today.

Doctypes at w3.org.

What's the deal with document.documentElement?  I thought it was document.body...  More doctype issues, especially good ol' IE, at document.body, doctype switching, and more.

Good gosh, how many times have I looked at this page:  $_SERVER[’PHP_SELF’], $_SERVER['REQUEST_URI'], and $_SERVER[’SCRIPT_NAME’]?