At this site, teachers and student teachers can find educational resources supported by federal agencies. The subjects covered include Arts & Music, Health & Physical Education, Language Arts, Math, Sciences, World Studies, US History Topics, and US Time Periods. FREE provides links to instructional resources (including video and audio), lessons and activities, case studies, fact sheets, quizzes, online books, and online exhibits.
This is a great portal to search for Common Core-aligned resources.
Resource URL: http://www.free.ed.gov/