One of the most classic ways of developing for the web is a LAMP or WAMP stack.
Linux or Windows + Apache + MySQL + PHP
Apache = http server
MySQL = database
PHP = server side scripting
For client-side, in-browser stuff, there's JavaScript.
You would also need to learn HTML to actually make a web page.
Edit : I also think Java is really good for socket-level programming as well. I know C also supports sockets but I've never tried it. Java seems more get-up-and-go though.
