I have many attributes which are stored in an Excel table. They refer to USA counties. I need to somehow connect those attributes to polygons in some format (don't know which is the best) and visualize it by Leaflet or similar API. Those attributes need to be in popups.
What do you recommend? How can I connect spatial data (polygons of counties) with attributes stored in Excel table? I'm using software like ArcGIS and Quantum GIS. I am opened to MySQL and PostgreSQL regards to databases if you recommend those.
Please try to explain with more details and exact steps so I can be sure I understand.