A couple of years ago, I was working on the creation of an online/hybrid High School. Here are a few of the resources that we found. I will update this post as more emerge.
Make your own games
Create your own online classroom
Moodle - One of the easiest and versatile ways to create an online classroom.
Project Foundry - Create Student guided, educator directed Project Based Learning
Teach Mate - Find someone to learn or teach.
Khan Academy - Quality tutorials created by Salman Khan on a variety of topics. Popular with teachers all over the world!
TED Talks - Hear inspirational and informative talks from people around the world on a variety of fascinating topics.