according to google maps, it will take between 1 hour and 48 minutes and 2 hours and 10 minutes [depending on traffic]. I don't believe there is any weekend morning rush hour, so i'd guess on the lower side of that range.
Depending on where in Chicago, and where you are going to park there, I would give yourself more than two hours
It won't be too busy on Saturday or Sunday, but the freeways into Chicago (90/94, which you'd be using) can back up suddenly anyway. I'd budget two hours, but if you're lucky, you'll do it in an a little over an hour and a half.
Depending on how fast you drive. I always allow an hour and a half to make room for any traffic delay that may happen. Sunday is usually a pretty good travel day and at that time you should be fine. I have found that it is always faster to go from Chicago to Milwaukee than Milwaukee to Chicago.
The early morning on the weekend is usually pretty smooth sailing. I would leave by 7 AM and you should be golden.
Get a list of you major assets that depreciate like a car or TV with the cost to replace. Divide the cost by the number of years that you will have the asset. That amount is what you save each year. Once you have a Sinking Fund, you can avoid debt.
See the link below and read about the Replacement Cost Budgeting.
source:http://guidestravel.info/archives/218