OK, first, congrats! It’s gonna be a cold move though.
Second, if it’s in River North, that’s good. Lots of public trans runs through there which is important to note because you probably won’t have any place to park.
I’m going to suggest craigslist as a place to start, but caution you to only work with reputable actors in the rental game. My current experience tells me groups like apartment people, apartment savvy, urban lux as well as all the big realty firms are generally ok to deal with.
Use your gut, if it looks shady, if there are misspellings in the ad, pass.
Realtor.com is another place that works for rentals as well as our beloved Chicago Reader classifieds. In Chicago, the brokers are paid by the landlord so generally the services are free to you. If someone wants to charge, run away.
Depending on your budget, I’d say take a look at These places
New, nice, close to everything with the promise of much retail space in the same complex.
Finally, This Document is one you’ll want to get to know. It’s the RLTO, Residential Landlord and Tenant Ordinance.