Scratch
The original(?) drag-and-drop coding system for kids. Visit the site, set up an account and click “Create” to get going.
Scratch Jr
A version of Scratch aimed at younger kids working on tablets.
Snap
A HTML5 alternative to Scratch, similar in idea but with some different features.
Code.org
A visual, “guided” introduction to coding for ages as young as 4 and up to 18.
CodinGame
Learn coding by programming the game while you’re playing
App Inventor
Make apps for Android phones and tablets
Alice
Alice is a bit like scratch at first, but aims to teach fundamental programming concepts as well as things like object-oriented programming. You need to download and install it first. It’s pretty big, so allow plenty of time!
Codecademy
Interactive tutorials for many languages, including Python, PHP, Java, Javascript, as well as HTML, SQL, Git and more.
Khan Academy
An enormous collection of tutorials, not just IT, but also science, maths, arts and economics.
Django Girls tutorial
Django Girls is a group working to encourage women to join the world of IT. In particular they work with the Django web framework, using the Python programming language. Their excellent tutorial will get you up and running from zero to a working web application in a few hours.
W3Schools
One of the best-known reference websites for web programming.
Stack Overflow
Probably the single most famous and useful Q&A programming website, used by millions of professional programmers across the world.