A centroid is a geometric center for a polygon. Centroids are typically used when you want to display a point / pin on the center of a polygon (shape).
To obtain centroids from a shapefile, you can quickly calculate and extract the latitude,longitude point using Quantum GIS. More on editing shapefiles
1. Open Quantum GIS
2. Select Polygon Centroids menu item Vector>Geometry Tools>Polygon Centroids
3. Name the shapefile and click save
4. Select Export/Add Geometry menu item Vector>Geometry Tools>Polygon Centroids
5. If you have multiple layers in Quantum GIS, make sure you select the later with the centroids.
6. Click OK.
7. Now X/Y data columns are added in a latitude/longitude format.
8. Open the DBF file inside of Excel.
9. Concatenating the YCOORD,XCOORD columns will give you the lat/long data for plotting points in your dashboard.
