POPULAR SITES TO LEARN BASIC WEB DESIGN

Html+css

http://www.w3schools.com
http://html.net
http://learn.shayhowe.com/
http://htmldog.com/
http://www.codecademy.com/en/tracks/web

Javascript

http://www.learn-js.org/
http://www.w3schools.com/js/
http://www.codeavengers.com/
https://developer.mozilla.org/en-US/learn/javascript
http://javascriptissexy.com/how-to-learn-javascript-properly/
https://www.codeschool.com/paths/javascript

PHP

http://php.net/
http://www.w3schools.com/php/default.asp
http://www.homeandlearn.co.uk/php/php.html