For new Chowhounds there was an absolutely outstanding post September 1, 2003 by Mike G which put together many threads on this board.
It was called THE EVER MORE UNOFFICIAL CHICAGO TIP SHEET/FAQ v. 1.1 and had information on many types of food from hot dogs and Italian beef sandwiches to fine dining. Ethnic cuisines were covered at length. I've posted the link below.
It's a great starting point, but remember that a lot has been added since. There is a search function on the chowhound main board. Also, you can use your browser's search function.
For those who want to join the listserve, Cathy2 posted instructions yesterday.