This is an excellent blog for those of us that teach chemistry and/or physics. It is run by Tammy Skinner and she is a high school science teacher.
Why I followed: It is really tricky to find a good, up to date blog about chemistry and physics. Tammy gives so good ideas and resources that I or anyone could use in their classes. If you are unfamiliar with a concept, she provides excellent notes so you can learn it your self.