Teachers.net publishes a monthly newsletter called the "Gazette." Among my favourites are the columns written by Harry and Rosemary Wong. Some of my top picks:
Alfie Kohn writer and speaker on human behaviour, education, and parenting. A personal role model of mine!
Use KeepVid to download YouTube videos and save them beforehand to avoid internet connection issues in the classroom.
Padlet is an online interactive bulletin board where students can collaborate ideas and share resources. See an example of how I've used it here.
Use Kahoot to create quizzes that link directly to student's cell phones, tablets, and laptops. Students sign in with pseudo-names and the app scores and ranks them as they progress through the quiz. Makes for a fun formative assessment.
Engage learners in teacher-paced or student paced activities and quizzes on Socrative. Results are automatically updated and managed in real time to give you feedback as it comes in!
Flipquiz allows you to create jeopardy-style quizzes for your students, great for unit reviews!
Create an interactive video learning experience for students with Zaption. You can edit youtube videos and add your own questions to them.
Dan Meyer is a huuuuge teacher crush of mine. He regularly updates his blog (dy/dan) with lesson ideas and his thoughts about topics in mathematics education.
Which One Doesn't Belong. Students compare four images and decide which is the odd one out. Any four of the images are possible answers. Great starter activity to work on reasoning and communication skills.
betterQs Blog. A collaborative blog by teachers looking to improve their questioning styles. Here's one I absolutely LOVE that was recommended by Ve Anusic on Reversing the Question.
Visual patterns provides a database of patters that can help students explore a variety of number patterns.
YouCubed is developed by Dr. Jo Boaler, a Professor of Mathematics Education at Stanford University. Get the scoop on the latest research in mathematics education, as well as access to rich tasks, videos, and resources.
The Oatmeal created a series of comics on proper grammar (e.g. how to use a semicolon, commonly misspelled words...etc.). A useful information for any classroom even if you don't teach English.
Flinn Scientific offers a ton of free science resources for teachers. There are some great resources for lab safety, information about lab techniques, video demonstrations, student lab activities and more.
ChemMatters is a magazine sponsored by the American Chemical Society that helps high school students find connections between chemistry and the world around them. You can opt in for paid quarterly subscriptions, or search through their past content. They also provide teachers guides for a variety of different topics.