Personal Learning Network Sites(sites where you can share ideas with and learn from othe educators)
Classroom 2.0 Live!
Watch, listen, and/or participate in some fantastic webinars that give you new ideas for teaching
http://live.classroom20.com/index.html
eduTecher.net
Share fantastic educational websites with others and see video demos on how to use great educational sites...all free
http://www.edutecher.net/
Learn Central
Attend free webinars conducted by teachers just like yourself or conduct your own webinar through Elluminate
http://www.learncentral.org/
SimpleK12
Participate in FREE webinars that demonstrate some really cool websites and web 2.0 tools that you CAN use in your classroom. A premium version is available for access to more webinars, but it is not free.
http://blog.simplek12.com/

Social Networking Sites for Schools
Collaborize Classroom
Extend classroom discussion to a structured and online community
http://wecollaborize.com/classroom.html
Edmodo
An educational social networking site for classrooms; only students registered to an Edmodo class can see the posts for that class; parents can sign up to see only the posts from the teacher and the posts of their child
http://www.edmodo.com/
Edublogs
Create and manage student and teacher blogs including videos and podcasts. Edublogs boasts it's "safe, easy and secure."
http://edublogs.org/
Wiggio
A free online toolkit that makes it easy to work with and coorinate groups; share and manage files, a group calander, poll your group, post links, set up conference calls, chat online, send out mass text messages, and send voice or email messages to the entire group; great for classrooms
http://wiggio.com

Free Websites for Your Class
Google Sites
Make a professional looking website through Google
https://sites.google.com/
School Notes
Create notes for homework and class information and post them on the web in seconds using this free service
http://www.schoolnotes.com/
Weebly for Education
Create a free class website
http://education.weebly.com/