My goal is to set up a map that connects census tract data with some other census data, e.g., population or median income.

Census.gov API

First, I found the SunglightLabs Census library, which provides a Python wrapper to the 2010 Census data API (wow!):

I requested a key from census.gov here: http://www.census.gov/developers/

And waited.........

Mapping Census Data

To map census data, I wanted to get shapefile information. Here's shapefile information provided by the Census Bureau: http://www.census.gov/cgi-bin/geo/shapefiles2010/main