Welcome resident. I would recommend you read Walpola Sri Rahulas "What the Buddha Taught"
. It doesn't get more basic than that (without being overly simplisitc either). He is a Theravadan but the issues he addresses in the book: four noble truths, karma, noble eightfold path, dependent origination, etc... are common to the great majority of schools/traditions of Buddhism.
Also, given you are in Chicago, I imagine there would be a wide range of Buddhist schools available there. Go check them out until you come across one that goes "click" for you. Don't be afraid to ask dumb questions. If you are treated with scorn for asking dumb questions then leave.
Good luck on your search and I hope we can be of help to you here at Dharma Wheel.