Now that you have heard from the tourists and the city does have a lot of great tourist spots, I will recommend some off-beat things.
Visit the campus of The University of Chicago. Wonderful Gothic architecture. You will not believe you are in Chicago. Time your visit for the daily noon-time carillon concert at Rockefeller Chapel. You can go up to the carillon loft but then you also to the top of the Chapel for a wonderful panoramic view of the area plus close ups of the gargoyles. And across the street from Frank Lloyd Wright's historic Robie House. And, finally, rest your feet in the absolutely charming and peaceful Bond Chapel.
Go to the "Maxwell Street" market on Sunday morning. No longer on Maxwell Street but close to it, it is a great place to take pictures of the eclectic whether people or things.
The city has two wonderful conservatories: Lincoln Park and Garfield Park. The former is in the lakefront zoo. The zoo is, well, a zoo and not that photogenic unless you like your animals in zoos. While both conservatories have great flowers and the buildings are contemporaries of each other, I prefer the more out-of-the-way Garfield Park. Across the street from the Zoo is the Noterbart Museum that has a great collection of live butterflies. A photographer's delight.
If you like photographing neighborhoods and old homes, walk thru Hyde Park where The University of Chicago is or the side streets near the Lincoln Park Zoo. Try the neighborhood restaurants, especially the ethnic ones.
Try the photogenic Art Institute of Chicago. Ho-hum photo displays. Down the block is Columbia College that has good photo shows. Take the walking tour of the Loop with
http://www.aiachicago.org/sightseeing_in_chicago/architecturalTours.asp. Wonderful historic architecture.
A great place is the chess pavilion just south of North Avenue and the beach. More eclectic shots plus a fabulous panorama of the north side of downtime. Bring your tripod with bubble level to capture the view.
Sun rises to the east over the lake. It is late enough in October that you can get out to a lake front park for a great view. Forget about sunsets in Chicago unless you like a lot of city clutter in them. Avoid the big commercial restaurants for the more interesting and affordable local ones. If you like theater, then take in a play at one of the wonderful neighbor theaters. Buy your half-price tickets downtown.
Enjoy your stay in the city and ignore those paranoid comments above from people who do not know the city. Sure, the city has its problems but these locations are the safest in the city and as safe as any other American city. However, use common sense and avoid unnecessary risks as you would anywhere.