We, at Six Feet Up, book most of our trips using the Kayak.com search engine and highly recommend it.
You may want to land directly at the Indianapolis International Airport (code IND) or try your luck flying to either Chicago (code ORD; 4-5 h drive to Indy) or Cincinnati (code CVG; 2h drive to Indy).
If you have plenty of time, good old Amtrak has a station downtown Indianapolis.
Address: 350 S. Illinois St.
Indianapolis, IN 46225
Phone: 1-800-USA-RAIL (1-800-872-7245)
Indianapolis is the "Crossroads of America" with interstates 65, 74,70 and 69 all running through it. Traffic is rarely an issue for visitors used to much more congested coastal cities.
If you get lost, feel free to call our Six Feet Up concierge at 415-320-3308.