If you have an interest in the spatial sciences, you'll enjoy the EdCommunity website from Esri. The Education Maps and Data area contains several dozen interactive educational modules designed to teach people about geographic information systems (GIS) and a range of visualization tools. The Lesson Plans are another great find, including hundreds of lessons from "Analyzing Supermarket Access With ArcGIS online" to "An Easy Pathway To Create Storymaps.” Additionally, the Videos and Webinars area includes student GIS presentations and useful webinars such as, "Where Do You Start with GIS in Education" and "Analyzing 10 Landscapes using ArcGIS Online.”