It's just across the border from Indiana, like 35 minutes from downtown Chicago. It's kind of crazy... the weather is always shitty, its impossible to park, there are way too many fucking people around, etc. They used to let homebrewers bring kegs and bottles to trade and let people drink, but I don't know if they allow that anymore. They also do something where you had a chance to get a "Golden Ticket" which, if you had one, let you buy a rare Dark Lord variation for $50.
The food is terrible and there is nowhere good to eat around there either. Basically the best thing to do is show up at your ticket group time slot, buy your allocated bottles, and get the fuck out back to Chicago unless you are a huge beer nerd who wants to trade rares. As far as I know its never sold to the public outside of this event so you have to trade or buy it off ebay or craigslist if you don't go to Dark Lord Day.
It's definitely worth a weekend though. The best brewery in Chicago is
Half Acre Beer Companyand they just opened a tap room too.