Google + Communities to Follow (and collections)

I know it didn't ask about following collections, but I saw some good ones for that, too.

Collections:
- STEM on Google+
- Science on G+
- ADHD Teaching Strategies
- Teacher Tips and Tools
- Academia, Schmacademia

Communities:
- Creativity in the Common Core Classroom
- STEM Educators
- Ask a Google Education Guru
- Flipped Learning