Obviously, if you have the cash, downtown is the best area to stay in. Close to all that's happening. Second best in my opinion is the O'hare area (very safe - have no fear of walking around at night). Stay at one of the hotels with access to the "L". The "L" is part of our extensive public transportation system. All routes meet in downtown with various legs heading out to different areas of the city. The blue line originates at Ohare. The first few stops have a lot of hotels, Hyatt, Radisson, Hilton, Marriot, etc etc. You'll need to shop for the best prices. The "L" will take you to the heart of downtown. Spend a day shopping on State Street, Marshall Field's is there. And then walk down to Michigan Ave and spend time in Millineum Park, see the Bean, Cool off in the fountain. You can even rent bicycles and ride up and down the lake front on the bicycle paths. Beautiful ride!!!

My favorite thing to do in the city is to take the Wendella Boat Rides up and down the River and into the Lake. You will get a bird's eye view of some of the best architecture in the city. Learn some history and go through the locks and hear how the course of the river was reversed! About 2 hours and it leaves from Michigan Ave and the River. Afterwards, walk around the corner and take the water taxi to Navy Pier. Shopping, theatre, restaurants, children's museum, Stain glass displays, 3-D rides. Enough for the whole day and evening. Check out the website for info on the fireworks.

There's always our Aquarium (dolphin shows, beluga whales, penquins), Art Museum (Chagalls, Grant Wood, minature rooms) Field museum of natural history (See Sue the most complete T-Rex ever).

Of course there are the Cubs, Soxs and Bears if you are of that mind. In the evening, want a laugh? Try Second City on Lincoln and North Avenue. Or House of Blues in Marina City (downtown).

Restaurants - what can I say. We love to eat here! For Indian, you can't beat going to "Little India" on the northside on Devon Ave. Restaurant after restaurant. Shop the Sari shops and cheap electronics. We do have a China Town of the south side - 22nd Street. Restaurants and shopping.
The Lincoln Park Area (north side) is probably best known for all kinds of restaurants from American to French to Sushi to Ethiopian. Quinsential Chicago food? Hot dogs and Deep Pan Pizza. There is actually an entire thread devoted to Chicago Pizza.

These are just general ideas. Give us more info for specifics.