Chicago Trip- Tour Needed!

Hello Friends, I will be traveling to Chicago on June 27th-29th for a Business trip. I was wondering if anyone is willing to give me a tour around Chicago; if not that's fine. But can I get some information about the best attractions in Chicago and the cheapest and easiest transportation? Also I love night views, where are the best places I can capture Chicago's skyline and take night pictures? I will be bringing my Canon EOS 20D and would like to capture some great pictures.>