I made this wonderful find today.
It's called Code Cademy. It's a site where you can learn how to code for free.
It's set up so that you can learn how to code in the form of a course.
It has it's own code/preview system built right into the course, so you don't need anything extra.
From what I've seen, it's completely free, and it has multiple coding languages to learn as well as learning about APIs.
http://www.codecademy.com