Chicago is undoubtedly the heart of Illinois. As far as "huge" goes (skyscrapers, etc) it is not too unlike any other city, particularly New York.
Because I had a mixed batch by age aboard my family tour, bars, and the like were left out of the question. Instead I visited the museums and took a few days looking around, to get acquainted with the locals and so on. Chicago may be seen for the "diverse" (aka "artsy"), the mainstream, and the drifting nobody. It is a cultural base, very like other large cities in that it is progressive, rather liberal, and big in every way.
When I first came to Chicago it was when I was much too young to remember, so my memory didn't help an inch in my second visit. For one thing, I could not recollect the toll stops. Speaking to the western local, these are stops where every few miles or half miles you are stopped to drop a few quarters into a box before continuing driving down the freeway. This may be a common ordeal for the Easterner, but toll stops are practically unheard of in the West, particularly in Oregon, where we don't even have a state tax (it was lucky, nonetheless, that quarters had started accumulating along the trip).
Next were the people themselves. It is true that nobody can be so radically different than one's own familiar sphere of influence, but each region has its abstract flavor. Chicago residents, so diverse in their own right, are generally well meaning and easy to get along with, assuming politics and social science are left out of the equation. What I found out the hard way was that some can be like bulls in china shops if prodded. This may or may not be much of a question for tourists to consider, but basically it is not an important one in my opinion.
Being away from the West Coast what seemed to me for the first time didn't relieve my experience when I accidentally turned the wrong street and ended up in a dead-end, in the worst possible part of a poor black ghetto neighborhood. Not that none of us have never seen a bum, or the products of these neighborhoods, but it certainly is worth noting that they are not afraid to confront you for money on the sidewalk.
Quick Tips:
Every place you visit will instill in your mind a visual thumbs-up or down to its good and bad advantages. Chicago, while not fatally expensive, is quite capable of burning holes in purses and wallets at frightening rates just for a dinner (a thumbs-down from my finance conscious mind). If you are a thrifty traveler, one shortcut I advise is to start packaging a carefully set inventory of food to last the trip before departure, if traveling by car. On the other hand, you could eat out at Wendy's or buy food at an inexpensive store like Dominics or Walgreens. If you have to sleep somewhere, your car will always have to be the last alternative, so bring extra blankets in case of untoward circumstances.
Parking is also another place where the money can sift through your fingers like sand. Because of this, you will either have to make due with expensive (and limited time) parking, walk everywhere throughout Chicago or look for a lone lot behind a neighborhood somewhere, where it is more likely to find your car smashed to bits when you return.
Nothing is truly cheap in Chicago, even the museums where you can spend over hundreds of dollars visiting in a week. But with some wise thought, the most can be made on a semi-frugal schedule.
And take plenty of quarters.
Best Way To Get Around:
Because I happened to have rented a car, I was not entirely dependent on taxis and buses, which was a good thing considering the herd I traveled with. This is perhaps more time saving and economical, though not walking about Chicago cannot ultimately be done in order to get around. Buses and subways are often crowded places where it is easy to find trouble. Walking and driving a car are most recommended.