Look no further than edweb.net. This free site is home to hundreds of learning communities. I first joined the site when I saw this community- Emerging Tech: Using Technology to Advance Your School Library Program. Even though I am not a librarian or media specialist, I found the content fascinating. I now belong to several technologies and media focused groups. This is a development community- I just saw a post to join a Literacy and Common Core group.
In addition to the wikis, blogs, and discussion- by far the best part for me are the monthly webinars. While I am not free (the sessions start around 3 or 4 in the afternoon), all the session are recorded and archived. Some communities have over a year of webinars. You can watch them later, then take a short quiz and get the PD certificate. In the last month I attended a live webinar on infographics as well as the flipped classroom and viewed a recorded session on twitter in the classroom. And before school ends, there is one on the iPad and assessment.
Join the network and take advantage of the free resources.