Web Design
   WebPagesThatSuck -- design issues
   The Dao of Web Design -- published by John Allsopp on "A List Apart"
  Web Page Design for Designers -- detailed explanations of how type and graphics work on the Web   
  WebDesignHelper -- free Web templates, menus, buttons, etc.

Web Programming
  WebKnowHow.Net -- links to many resources for web programming
  Dr.Html -- web page validator
  World Wide Web Consortium -- specifics of web standardization
  W3 Schools -- comprehensive Web developer tutorial site

Server Issues
   Server watch -- articles and resources for popular web servers
   Browsercam -- view website through several different browsers
   The Counter -- general browser usage statistics based on global statistics

HTML
   Hitmill -- basic tutorials
   HTMLCodeTutorial-- basic tutorials and documentation

JavaScript
   Hitmill -- basic tutorials
   DevGuru -- great reference for JavaScript objects

ASP
   ASP from A to Z -- workshop from the source (Microsoft)
   ASP 101 -- everything you ever wanted to know

PHP
   PHP -- official PHP web site

Perl
   Perlmasters -- everything you ever wanted to know

Java Servlets and JSP
   JSP -- information JSP
  Java Servlets -- information Java Servlets