Chicago has a host of activities that make the season bright: the Magnificent Mile Lights, Christkindlmarket Christmas Market at Daley Plaza, Winter Wonderfest at Navy Pier, Santa House at Daley Plaza... Reed about December events at About.com's Chicago Travel site, or at Explore Chicago.
Also great for visitors is the Chicago Greeter program: similar to New York City's Big Apple Greeter, local volunteers offer a personal introduction to their city. Normally visitors sign up for a "greet" but during the holiday season, a Chicago Greeter "Magnificent Mile InstaGreeter" service offers free one-hour walks, first-come first-serve.
Meanwhile, the Chicago Botanic Garden has events for families: Christmas breakfasts and suppers with Santa and Hot Chocolate with Mrs. Claus, each including a visit to Wonderland Express (pictured above), a magical display in which miniature trains travel past tiny versions of Chicago landmarks. Several nearby hotels offer discounts if visitors ask for the Chicago Botanic Garden rate.
See also holiday offers at multiple "Magnificent Mile" hotels: packages variously include gourmet chocolate, breakfast for four, savings at Navy Pier, and other goodies that families will appreciate.