This is an incredibly useful site! There are teaching materials and lesson plans for all levels. But the best part is the extremely well-designed search function. Search the web for museums and historic sites or multimedia content. They have a section of website reviews, which could be a great timesaver!
This site has a library of science activities and lessons, plus links to many other websites.
These learning kits on different countries are designed to promote global citizenship.
Self-paced, online coding classes for ages 7 to 15.
This site provides group buys for homeschoolers.
This is a wonderful website from Stanford Math Education Professor Jo Boaler.
This is the organization that publishes Poetry Magazine.