See what they sell for.Over time you will get a sense of the market.You can pull data off the web, you can look at listings and sales online but there is no substitute for putting eyeballs on these properties.2.

I might add, though I don't currently have any REI, that after looking in the northwest area of Chicago for the past 5-6 months it would be wise to truly ensure that no serious CapEx will be coming your way.  455k seems on the cheaper side a for a full legal 3 unit in Dunning that is turnkey. 

We are now hoping to get in touch with a local accountant who we can trust to ensure we do everything we can to file correctly and get the most out of any tax benefits we may now have.

Another important is crime and that data is available as well.   

I negotiate payment plans to ensure that we are not only providing a great service to your tenant but ultimately, making sure that our owners have consistent income generated from your properties.  

I want to respond, in a general manner, to the concept of "why fix it " or "put in less quality than was there before"   Unless you have D quality rentals the above is a quick way to ensure your quality of tenant, amount of rent and value of asset all go down while your maintenance bills all go up. 

This is a great question and a question many new investors have.The best way to ensure your success in this business to have solid comps for your subject property and to know your numbers down to a science.

Let's keep this on the data.

I am having a hard time finding many resources that describe how to get data to make informed decisions and how to analyze a deal.

In this case, it is the borrower's responsibility to ensure that he is able to generate the cashflow needed to service the debt.