Written by George Siemens, this article outlines the necessity of a new learning theory that addresses the impact of the Web 2.0. By explaining behaviorism, cognitivism, and constructivism, Siemens provides the argument for connectivism in the digital world. The article is a starting point for anyone who needs a working definition of connectivism or wants to compare it to other prominent learning theories. He presents the idea that "the pipe is more important than the content within the pipe."

For Moodle users, this site has everything from webinars to updates. It is very helpful.

Edutopia is one of my go-to sight. Here is an article on using Twitter for professional development.
http://www.edutopia.org/twitter-professional-development-technology-microblogging