Their open house is on April 5 from 1-3pm. Maybe, you could just call and ask if you could visit during that period? I doubt they'd say no. And if they didn't have to plan anything special for you, then you won't have to be worried about annoying them or taking up their time.
I do know that they have graduate assistants in the CDIS department. But I'm not sure how many. And I'm not sure how much of tuition is waived either. But their tuition is definitely among the cheapest I've seen in Illinois.