This particular entry addresses twitter, but there are many great things on this blog. How cool that a husband and wife blog together (can't imagine that happening at my house!) They include various resources, including history and elementary ed.
"How about a Pinterest board of all my best teaching resources? These are my top pins, most-visited web pages, and blog posts with the most visits - all in once place!" Laura Candler already had many great resources posted on the web; now she's adding them to pinterest.