ArcGIS for UC ANR owned computers free of charge
ArcGIS is also commonly free or deeply discounted for students through your local college or university. A free 21-day trial version of ArcGIS can also be obtained through Esri here.
Quantum GIS is an outstanding free and open source GIS software.
(Note: The 64 bit Windows version of QGIS can occasionally be more glitchy than the 32 bit version, even on a 64 bit computer)
For a good introduction to using QGIS, check out the QGIS Tutorial by Nate Roth
Google Earth Pro is an extremely useful and easy to use platform to locate and map features anywhere on Earth and is now free to download and install on your computer.
DNR GPS is an outstanding program for processing GPS data, provided for free by the Minnesota Department of Natural Resources.
CartoDB is an excellent online service for developing and hosting online maps.
Google Fusion Tables is an easy to use web mapping application that accepts Google Earth KML files.
If you do not already have a Google account, you must first sign up for one here. Once signed in, go to Google Drive. Click Here and then click the “Create” or “New” button in the upper left hand corner and choose "Fusion Table" (Note that you may need to select Fusion Tables from the “Connect more apps” if it is not already in your list of available tools).