I'm gonna give you a single blanket answer that is, it depends. Here are a few tidbits of info:
Real Estate Taxes (estimated 4% purchase price)
Rural northern illinois is very broad. It depends on the county. I suggest you find a similar comp on the MLS/pseudo MLS sites and see the tax information for the previous year. You can also call the county assessors office.
Property Insurance (estimate 0.75% purchase price)
What's your purchase price? 0.75% on 100k is $62 per month, while 0.75% on 500k is $312. Multifamily and tax go along the lines of economies of scale. The more units you have, the less insurance/unit.
Property Management (11% rental income)
I think 11% is a good, conservative number. The more units you have, the bigger discount you can get though.
Repairs & Maintenance (10% rental income)
10% is a solid amount.
Utilities ($75 water / month / unit + $25 trash)
Call the local utility provider and ask them for an the average water bill amount
Lawn care (estimated $100 / month x 6 months)
$100 per month is way too much if you're buying a duplex. As always, it depends on the size of the land. $100 may be a good estimate if you're buying a bigger multifamily on a big piece of land.
Snow plow small driveway / parking (estimate $100 / month x 3 months)
$100 again probably two much for a small driveway.
Capital expenditures (10% potential rental income)
10% is a good, conservative number for Capex. If the property is in newer/nicer condition, you could budget for less.