I was recently invited to participate on a site called Quora, where anyone can post a question about anything and those with answers can share their knowlege. For example:
Has anyone used QGIS, and if so, do you recommend that over other open source mapping software? I'm interested to know if Quantum GIS is a better option to Google maps or something else to share data visually around sanitation issues.
Comparing QGIS to Google Maps is really apples and oranges. Google Maps is NOT a GIS application, it is an online mapping platform. QGIS will let you work with PostGIS which is a very powerful geodatabase extension for PostgreSQL. A GIS program, like QGIS, lets you ask spatial questions like which points fall inside of these polygons? I recommend QGIS, but I also recommend you try the OpenGeo Suite (Community Edition):http://opengeo.org/community/suite/
I can also highly recommend this book, which provides a good intro to both QGIS and PostGIS:http://www.amazon.com/Desktop-GIS-Mapping-Planet-Source/dp/1934356069
N.B. QGIS is not a map server, so if you have data in hand and you're just looking to publish it online then Google Maps or KML for Google Earth would be an excellent choice. However, if you have a folder full of .shp files, you may well need to use QGIS to process them before your data will be suitable for Google Maps.