Census Explorer is a tool from the United States Census Bureau which gives quick and easy access to data on a number of popular topics, including "population estimates", "retail", "people, education, and income", and "commuting". The tool features an interactive map, and access to information from the 1990 and 2000 censuses, and the 2012 American Community Survey.
When you are interested in researching a topic it is best to start with a specific question. As an example, I'm going to pose the question: "Which areas in Georgia have the largest numbers of adults who commute by bicycle?" Here are a set of steps for rapidly pulling together an answer to that question. The graphics in this article are screen shots rather than live maps, but you can build the interactive maps and follow along in another browser window by carrying out the step-by-step instructions.
1) First, go to Census Explorer at http://www.census.gov/censusexplorer/
The opening screen of the current version as I write this article looks like this:
2) Since we're interested in data on commuting, we'll select "Go to Census Explorer Commuting Edition"
3) Click on the pull-down menu labeled "Select a Measure".
4) Since my research question involves the trends in bicycle commuting I'll select "bicycle" from the menu.
5) Next, select the pull-down menu labeled "Show by"
6) I usually start with a larger geographic area to get a quick overview of the patterns, then drill down into the smaller units. The largest unit relevant to my question is "County", so I'll start there.
7) I'll then double click on the interactive map to zoom in on Georgia, and adjust the size and position by manipulating the plus/minus icon and dragging the map around as needed.
8) The default data for the map is the 2012 American Community Survey. You'll notice on the map above that there are four darker areas in the Georgia portion of the map. These areas represent Appling County, Athens-Clarke County, Baldwin County, and Chattahoochee County. These are the counties with the highest percentage of people over 16 years of age who commute to work by bicycle.
The University of Georgia dominates Athens-Clarke, so I would guess that university towns have a larger number of bicycle commuters than average. Chattahoochee County is very close to Columbus GA, Baldwin County has Milledgeville as its county seat, and Appling is a rural county. Tentatively I'd guess, based on the counties with relatively high bicycle commuting, that both high concentration of students, and low income, could be contributory factors to increased commuting by bicycle.
Drilling down to the census tract level is where it really gets interesting. The census tracts with the highest levels of bicycle commuting are concetrated in metro areas, and a few metro Atlanta census tracts have the highest levels. In one Clayton County tract. more than ten percent of the commuters over 16 years of age commute by bicycle. Since any percentage over one percent is unusual, Clayton County is remarkable.
In order to draw valid conclusions about cycle commuting in Georgia, more analysis would have to be done. The Census Bureau has other tools to help with the process, including American Factfinder. But Census Explorer provides a good starting point. You can get an overview of a number of characteristics of an area at the state, county, and census tract level.