Chicago is an amazing city in the summertime. There's some sort of festival every weekend (sometimes more than one!), street fairs galore, music everywhere, and, of course, tons of people taking advantage of the lakefront and parks. This weekend is particularly exciting. The Printer's Row Book Fair is always a highlight of June. It's been going on since 1985, and has nearly 200 booksellers with stalls showcasing new, used, and antique books, as well as 90 different literary events on seven stages. Dozens of authors will be there for events and signings. Admission is free, but if you're a reader, you'll end up spending a fair amount of cash on books!
If music is more your thing, Chicago's Blues Fest starts June 7 and goes through the 10th. It's the 24th Annual Festival, and the largest free outdoor blues festival in the world. It's in Grant Park, featuring local acts and nationally known names like Koko Taylor and Zac Harmon. Music starts around noon every day and goes until about 9:30pm.
If you prefer art, try the Old Town Art Fair or the Wells Street Art Fair, which are within a short walk of each other this Saturday and Sunday. Both feature live performances as well as juried art competitions. There's a wide range of materials used and price ranges as well.
For serious gastronomy (and the chance to experience some interesting neighborhoods), try Ribfest Chicago, Andersonville Midsommarfest, or Fiesta Back of the Yards. And if none of the rest of this excites you, there's always the Chicago branch of the World Naked Bike Ride (we kid you not) to protest reliance on oil. It's June 9, and the ride begins at 9pm (body painting starts at 6pm).
This is a fairly typical line up of events for a Chicago summer weekend. You can keep up with the schedule in a variety of places. If you're moving here soon (or want to give a gift to someone who is), a subscription to Time Out Chicago is a great idea - it's a weekly magazine showcasing all the great things there are to do in Chicago.