This site introduces Japanese lesson study which is a collaborative effort by groups of teachers to understand how their lessons impact students. Elements included in this type of PD are collaborative lesson planning, observation, iteration and reflection.
This site challenges students in grades K-8 to say "I can" to solve social problems. The contest is held every year and takes in entries from all over the world.
Open access archive of webinars dealing primarily, but not exclusively, with support for ADHD students.
Pedagogically sound and research-based, but some hosts, like the ADDitude site itself, trend towards a blame-teachers perspective in "defense" of students/families/etc.
Still, a fantastic resource.
Formerly known as ReadItLater, this browser extension allows you to save sites that you want revisit later with just one click of a button. It's easy to install the button in your toolbar and can help cut down on the number of tabs you keep open. You can search by tag or key word and if you have it installed on your mobile devices you can read your saves while you're sitting around at the pool. :)