For GIS instruction, see http://k12.maps.arcgis.com, or shortcut http://esriurl.com/k12gis. See especially the first carousel button, "01.InstructionDocs." The Org contains instruction docs, movies, maps, apps, layers, groups, links, and more. All of the contents are usable by teachers and students alike.
Dear Charlie,
I just discovered your "Instruction with ArcGIS Online" message posted last August! Thank you for the link in your post. On the blog section of the ESRI K-12 Education page, I was introduced to Kolb's Learning Theories, and also to the book "Facilitating Seven Ways of Learning: Connections to GIS in Education" (Quote from the book: The seven ways include behavioral learning, cognitive learning, learning through inquiry, learning with mental models, learning through groups and teams, learning through virtual realities, and experiential learning.) I love this phraseology, and it puts into words how I believe students should learn. Thanks for a point in the right direction.
Now updated, with greatly expanded sections for maps & apps, docs, and videos.