Math curriculum for third grade through high school. There are video lessons to explain concepts, and step by step video solutions of every problem in the curriculum. I've seen and heard many great comments and reviews about this program. It's pretty expensive, and they apparently don't allow anyone to discount their products. But you can often find used copies on homeschool resale sites.
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.