Collaborative Learning Environments (CLE's) can be very useful and helpful for many educators. They can help link you to other teachers and you can share resources and ideas in a secure way. I've been researching two particular sites: Edmodo and Engrade.
Edmodo is social learning networking for teachers. It allows teachers to create online classroom that their students can access. Teachers create groups that students then join and then create assignments and quizzes for students to use. It also allows the teacher to store links and upload files so that everything can be in one place. Click here to find out more.
Engrade is a free customizabe gradebook for teachers. District can upgrade to an Engrade pro account that allows teachers to create digital lesson and 3rd party content making it easier for flipped classrooms. Upgraded accounts can also track student assessment data across the school, district, and nation as well as creating on line assessments. Click here to find out more.
Both Edmodo and Engrade look like great sites. I have created accounts for both and plan on finding way to use them in my Music teaching. At this time, I can't not recommend either one though I do feel that Edmodo would work best with upper elementary (Grade 5) and older students because it looks like an easy way to create a flipped or online classroom. I would recommend Engrade for any teacher who would like an easy way o keep up their gradebook.