A few recommendations for newbies:
First there's the Not For Tourists Guide to Chicago. It is a great guide for all the things that locals need in their neighborhood, that visitors don't, like public transportation, mailboxes, plumbers and suggestions from locals. Get a copy of the guide here.
Time Out Chicago is a great place to see what's up in Chicago this week; from festivals to special events at museums, free concerts, and reviews of the newest restaurants and bars. Online and in print.