Entity structuring, basis calculation (i.e. breakout between building and land), deductible expenses, etc.

Tools like the BiggerPockets calculator and books like The House Hacking Strategy can guide you further.

Build a strong team, including agents, lenders, and property managers, and use tools like the BiggerPockets calculator to analyze deals.

A financial calculator and legal pad might work in the hands of someone who knows what they are doing, but that doesn't mean it's the best way to do it.

Use a quitclaim or warranty deed to transfer the title, and be prepared to pay Chicago’s transfer tax, calculated at $7.50 per $1,000 of the property’s fair market value.

My conclusion is that take the provided ROI calculations from REI as purely estimates.

@Brett Coultas if you're a newbie, you want to be careful of an "investor friendly" agent selling you something they truly don't understand:(95+% of agents only know how to handle owner-occupied transactions - you can verify this by asking them calculate ROI for you or Cash-On-Cash!

The property itself should bring in revenue ( even if you choose not to live in one side) and generally a bank will accept a portion of that rental income into the calculation. 

Being a responsible person has nothing to do with the financial calculation for rate of return or cash flow. 

Here's a bit more in detail about how rates are calculated for DSCR loans:1.