ArcGIS Pro Tutorials
by Manuel “Manny” Gimond, Colby College.
Do you know where you are? - The Global Positioning System
by the National Oceanic and Atmospheric Administration (NOAA), 2017.
Documentation for ArcGIS
A launching point for documentation of all things Esri.
GIS Certification Institute
A non-profit organization that provides the GIS community with a complete certification program leading to Certified GIS Professional recognition focused on six key knowledge areas: Conceptual Foundations, Cartography and Visualization, GIS Design Aspects and Data Modelling, GIS Analytical Methods, Data Manipulation, and Geospatial Data
Geography Realm
An information site about all things geography (formerly Geo Lounge). Find information here about physical and human geography as well as guides for learning about geography and developing a career in geography.
Geography & Map Reading Room
The Geography and Map Division of the Library of Congress provides cartographic and geographic information for all parts of the world to the Congress, Federal agencies, state and local governments, the scholarly community, and to the general public. It is the largest and most comprehensive cartographic collection in the world, numbering over 5.2 million maps.
GIS&T Body of Knowledge
Provided by the University Consortium for Geographic Information Science (UCGIS), this Body of Knowledge (BOK) documents the domain of geographic information science and its associated technologies (GIS&T) in a new digital format to support the GIS&T higher education community and the increasingly diverse collection of GIS&T professionals.
GIS Lounge
News, data and information on GIS.
GPS: An Introduction to Satellite Navigation
The “GPS MOOC” by Stanford University, 2014.
Living Atlas of the World
The foremost collection of global geographic information from Esri and its partners, including maps, apps, and data layers used to support critical decision making.
Map Projections
by Jim Riesterer. Edited by Scott Hughes, Dan Narsavage & Diana Boyack. The Geospatial Training and Analysis Cooperative, 2008.
Mapping our Changing World
by The College of Earth and Mineral Science at Penn State University.
National Geospatial-Intelligence Agency (NGA)
Delivering world-class geospatial intelligence that provides a decisive advantage to policymakers, warfighters, intelligence professionals and first responders.
Open Data Charter
The ODC is an international charter with the mission to make data open and freely available, which protecting the rights of people and communities.
Projections and Coordinate Systems
The University of Washington Spatial Technology, GIS, and Remote Sensing in the School of Forest Resources (2010).
State Plane Coordinate System
Rich King’s county-level State Plane coordinate system reference also available as an MS Excel spreadsheet.
The Field Calculator Unleashed (pdf)
by Tom Neer, EDAW, Inc. ArcUser, pp 51–55 (2005).
The GIS Encyclopedia
by wiki.gis.com
The World Factbook
Regional and world maps provided by the United States Central Intelligence Agency
UNAVCO
Transforming understanding of Earth systems and hazards using geodesy.

Podcasts

Esri and the Science of Where
This podcast is to help executives and leaders in the industry and government understand how modern GIS technology enables digital transformation and drives growth.
Geodorable
by New Zealanders Chris Morris & Mark Thompson.
VerySpatial
Your source for information on Geography and geospatial technologies.

Online Articles and Textbooks

Essentials of Geographic Information Systems v.1.0
by Jonathan Campbell and Michael Shin (2011). Copyright © Saylor Academy Open Textbooks (saylor.org).
Geographic Information Systems, First Edition, 1991
Copyright © John Wiley & Sons 1991. Converted to HTML by Jim Harper. Last updated January 16, 2001.
Geometric Aspects of Mapping
Provides information on concepts of spatial referencing, including a brief introduction followed by more in-depth notes on coordinate systems, reference surfaces, map projections and coordinate transformations. International Institute for Geo-Information Science and Earth Observation (ITC), Enschede, 2009.
GIS as an Integrating Technology
Materials by Kenneth E. Foote and Margaret Lynch, The Geographer’s Craft Project, Department of Geography, The University of Colorado at Boulder. Copyright © 2000–2015.
GPS: The Global Positioning System
Maintained by the National Coordination Office for Space-Based Positioning, Navigation, and Timing (2018).
GPS Basics
Written by Aaron Weiss (a1ronzo). Available online at SparkFun Electronics. Accessed 18 January 2018.
GPS Tutorial
Trimble Inc, 2018.
Intro to GIS and Spatial Analysis
A compilation of lecture notes into an online textbook on data manipulation & visualization and exploratory spatial data analysis by Manuel Gimond.
Johannes Kepler: His Life, His Laws and Times
National Aeronautics and Space Administration (NASA), 2017.
The Global Positioning System
Written by Peter H. Dana, Department of Geography, University of Texas at Austin. 1994. Provided by Ken Foote, The Geographer’s Craft, Department of Geography, University of Colorado at Boulder. 2015.
The Nature of Geographic Information
An open-access textbook to promote understanding of the Geographic Information Science and Technology enterprise.