Code.org
Overview
Code.org is a nonprofit whose sole purpose is to broaden students knowledge and understanding of computer science as well as increase women and minority participation. This site provides free curriculum and is openly licensed under a Creative Commons license.
Hour of Code is a global effort to demonstrate the basics of computer science through coding with 1 hour coding activities with over 450,000,000 hours completed.
The website fits many types of classrooms and tailors itself to what students are currently interested in (such as popular movies, etc.). It is a great introductory tool for coding.
Coding Games at code.org
YouTube: Create your own sports game