I recently stumbled upon edWeb.net and I cannot say enough great things about it. In the short time I have become a member, I have attended several webinars with my teachers, watched archived sessions that I missed, made connections with other educators, and provided resources to my district about Common Core Standards. The membership is free and once you are logged in, you can search for communities to belong to such as PD in Action and Implementing the Common Core Standards. Many of the communities host live webinars and all sessions are archived and include the slides and recorded chat session files. In addition, the site includes personal profiles, live chat, messaging, polling, discussions, shared calendars, wikis, and shared bookmarks. Their user guide contains all the information you need to get started.