"PBS LearningMedia is a dynamic platform offering the best of public media content and produced specifically for PreK-16 teachers. With free access to over 14,000 high-quality resources tied to national standards, teachers can download, save and share exactly what they need for an inspired classroom experience."
"After 3 resource views, you will be prompted to create an account," although creation of the account is free. All of the materials are hosted on the PBS site.
One can search by grade level (Pre-K to 16+), subject matter, language, and accessibility.