For new visitors to Chicago: the most important information for orientation is to note that walking toward the Lake is going East. The University is located on the southside of downtown.
The Institute is located at 5640 S. Ellis Ave., Chicago, IL 60637.
There are two airports in Chicago. The primary international airport is O'Hare International Airport located about 50 minutes from the University depending on traffic.
The other airport is Midway International Airport which is located much closer to the University with a travel time of approximately 25 minutes. Note that Southwest Airlines has very convenient service to Midway but does not appear in most airline ticket search engines.
Information about Chicago airports can be found here.
Lastly, if traffic is very bad. The fastest route from (and to) O'Hare is the blue line train from the airport to downtown (Jackson/Dearborn stop). This takes about 45 minutes.
From downtown, there are four main routes to the University. One can take either a taxi, the metra train (55th-56th-57th stop), the #6 Jackson Park Express bus (southbound to 55th & Hyde Park) or the red line to the Garfield stop.
The metra stop and the bus stop are a 25 minute walk to the Institute west along either 55th-56th-57th streets all of which intersect Ellis Ave. From the Garfield red line stop, the #55 Garfield bus runs regularly with a stop at the corner of Ellis and 55th St.
The bus and L (subway) schedule can be found with a useful trip planner here.
If you are driving to the University, please use the map link under "Visitor Information" to map your trip. There is a parking garage located on the corner of 55th Street and Ellis Ave. which is the closest garage to the Enrico Fermi Institute.