This site goes over, in detail, what a community of practice is. I had a little trouble understanding what the concept was referring to from the class material, but after reading this site, I was no longer confused. It defines a Community of Practice and breaks it down on a basic level. It provides the three requirements and explains what a CoP basically does. It is very informative.

This is a huge social networking site for teachers using technology in their classrooms as well as online. There are many like-minded individuals and resources here.