My company uses a sales model of dealers, territory managers and regional managers, each with a different level of area scope (IE manage based on zips codes, states, or regions.)
I want to create a slimmed down map that is similar to this US state map that would allow our users to manipulate who manages what.
What are some good resources to start down this path?
I'd say you could base yourself on OpenStreetMap which database is under creative commons license.
KML and Tiger(US) or Maps and Geo(Can)? Or with something less interactive you could possibly still use the Topologically Integrated Geographic Encoding and Referencing system.
A combination of PostGIS for storing the data, MapServer for generating map tiles, and OpenLayers for the interface should give you something to start with. Include a some PHP libraries, and your are just about there!
One useful tool that I've found is the following GPS Visualization.
