Professional Development and Personal Learning Networks
Edutopia - If there is one site as educators that you should be a part of, it is Edutopia. It was vote 2012's "Best Group Blog" by the Edublogawards. It is a very practical site with not only blogs for anyone in education, but practical videos to see educators in action.
Teachers Domain - This site is associated with PBS. Videos abound for not only classroom use, but also professional development. Searches can be made by subject or standards.