QGIS

The open source alternative to ArcMap, but not as industrial strength. It's a GUI for composing maps and doing simple analysis.

How to:

• QGIS: File > Project Properties > General > Save Paths > Relative. Check.
• Create conditional labels in QGIS
• How to set custom projections (CRS) in QGIS (YouTube)
• Table Joins – A New Feature in QGIS 1.7:
• Spatial joins
• Delete columns in shape files with the essential "Table Manager" QGIS plugin
• View Web Mercator map tiles in QGIS - alternative post
• Running Scripts in the QGIS Python Console

Be aware: These are for version 1.7ish. Might be fixed in newer versions.

• No warning column can't support value in editing session. Displaying desired out-of-rage value, then on save trashing it.
• "Original CRS" really means "Project's Active CRS (data frame)", not the theme's original CRS in #QGIS.
• QGIS project-on-the-fly breaks geo-processing (though it draws pretty)
• Merging SHPs in #QGIS doesn't match column names but rather column order.
• Seemingly no way to import PRJ file to set new CRS and no easy way to duplicate and modify existing CRS in the list.