How many and what programming languages should I learn to be really good in web development?

Answer 1

@Martin: Check this link out for a complete roadmap for all kinds of web development https://www.sololearn.com/Discuss/281232/the-complete-web-developer-roadmap

Answer 2

For front end:
HTML
CSS
JavaScript

For backend:
PHP
SQL

Answer 3

For backend:
SQL & (.Net | Java | Python | Ruby | PHP)

Answer 4

To design a webpage:HTML
To add beauty to your webpage:CSS
To make the webpage dynamic i.e. to use by clients,linking to web etc..:PHP, JavaScript, SQL