I've done hill repeats at one of the suburban boat launches--but truth is bikes aren't allowed on that road, so you might get yelled at. Besides, riding up the access road five or 10 times still won't prepare you for the kind of long hills you'll find in Wisconsin and farther afield. You just have to do it. Get in your small chainring before the climb (if you shift from the big to the small under a load, you may shift your chain right off), and then shift as needed to your easiest cog and try to maintain a rhythm while seated. I think a lot of people make the mistake of trying to attack a hill when they don't have to. Which is one thing if you're racing, but if you're doing a metric century or other organized noncompetitive ride, it makes more sense to conserve your energy where you can. Stand up for the steepest parts, but you should be able to climb most any hill while seated.
The Evanston Bike Club says their Saturday 7AM ride includes some lake access hills. I'm planning on doing it this Saturday. I'll report back on the hills.
Without a doubt. when I was going to school up in Madison, I rode a few times with the Bombay Bicycling Club, including a ride to New Glaris. It was the best ride I'd ever done! The climbs were tough but doable on a double, while the descents and scenery made each climb totally worth the pain.My personal favorite is around the New Glaris, WI area - home of lots of hill bike riding on roads and trails plus the best damn microbrewery in the Midwest.