Curated OER
Water Quality and Watersheds: A GIS Investigation
Requiring more than one class period, this resource takes earth science learners on a journey through a watershed. Using ArcGIS Explorer, an online geographic information system, they view maps of watersheds and surrounding landscapes....
Wikimedia
Wikipedia: Geographic Information System
Gives in-depth information about GIS - its history, what it is, techniques and tools, applications, etc.
University of Colorado
University of Colorado: The Geographer's Craft Project: Gis as an Integrating Technology
A comprehensive overview of GIS as a technology that brings different kinds of geographical data together to create something that is greater than the sum of its parts.