This cute video explains how teacher-built Share My Lesson helps educators connect to get what they need. They offer user-rated Common Core exemplar lessons in their library of more than 250,000 resources.

LearnZillion is like the Khan Academy of Common Core, with thousands of lessons tied to the standards. Started by a school in Washington, D.C., as a homegrown repository for screencast lessons by their best teachers, they got funding to go big, and now teachers across the country can participate.

Open Education Resource Commons is an incredible repository of valuable free learning materials -- but it can be overwhelming to the new user. This video helps you search smarter while you navigate the nearly 50,000 assets contributed by hundreds of content providers.

They don't call me VideoAmy for nothing: I love finding videos to use in the classroom, and WatchKnowLearn is a wiki just for that. The site looks a little different now than when this intro video was made a few years ago, but the functionality remains the same.

PBS LearningMedia is a newly launched free service that brings together digital content from trusted organizations and public broadcasters, including videos, games, audio clips, photos, and lesson plans.

Though Shmoop is relatively focused on test prep, they offer study guides, lesson plans, and sample quizzes, written by PhD students. Start with their free Learning Guides section; you run into their tier of (reasonable) paid goodies pretty quickly if you start from Teacher Resources.

With more than 8 million users from nearly 200 different countries, Currikihas been a vibrant place to create, share, and find open educational resources (OERs) since 2006. They offer free tools for build-your-own curricula and private virtual collaboration spaces.

There are also some fantastic subject-specific curriculum sites, likeReadWriteThink, managed in part by the National Council of Teachers of English (NCTE). They offer specific how-to videos on their YouTube channel to help you navigate better while hunting for language arts materials.

BetterLesson houses how-to videos on Vimeo, so the only YouTube video I tracked down is this one, of founder Alex Grodd speaking about a new model for professional development. Although BetterLesson has fee-based subscriptions for districts, individual teachers will find lots of free tools.

This screencast tours us through EDSITEment, a project of the National Endowment for the Humanities. The site offers teaching materials organized into four categories: Art and Culture, Foreign Languages, History and Social Studies, and Literature and Language Arts.