For those going to Axpona, make sure you visit the city. It is easy to get to many major attractions by public transportation from the convention. Anne-Sophie Mutter is in town that weekend.
http://www.chicagoreader.com/
Great source for entertainment listings. Go to the individual sections to find the search functionality.
http://www.hottix.org/
Discount tickets to many events. Check during the week of the show.
http://cso.org/
The Chicago Symphony
http://www.harristheaterchicago.org/events/calendar
http://chicago.about.com/od/artsculture/tp/Top-Ten-Chicago-Museums.htm
http://www.transitchicago.com/airports/
http://www.greektownchicago.org/
Get off the CTA blue line at UIC-Halsted and walk a few blocks north on Halsted Street.
http://en.wikipedia.org/wiki/Chinatown,_Chicago
This is easy to get to via public transportation. From downtown, take the red line subway to Chinatown/Cermak. Make sure you get off there as the neighborhoods get rougher further south. On the platform, head to the north exit (towards downtown) for where the Chinese eat. Head south to go where the tourists eat. The sights are more interesting where the tourists eat.