Quantum GIS (QGIS) provides much of the same functionality as Esri’s ArcGIS software (basic level) and has developed into a robust open-source alternative. The term open-source refers to the fact that the source code for the geographic information system (GIS) program is available to anyone, so people can try to improve and add to the software. The QGIS coding community has worked diligently to improve the program and add features in recent years.
There are many YouTube videos demonstrating how to use QGIS. Here are a few recorded webinars from Vermont Center for Geographic Information (VCGI) to give you a start:
Make sure to check out the Map@Syst webinars for upcoming and previous QGIS events.