I downloaded a contract, but want to make sure I'm not leaving anything out in regards to Illinois specifically.  

Then, download the BiggerPockets Ultimate Beginner's Guide and start reading some more!!

Once you're established, have multiple properties, or it's a business, then I suggest as others and request a document review and an hour or two from an experienced real estate attorney.You probably need something in place, but please don't try creating your own or download a generic non-MN one from a blog.

BP also offers a landlord forms package you can download.  

Download BP’s newest book here some good due diligence in Chapter 10.

Just downloaded it to the iPad

Download Creditkarma  app it free and tells you exactly what you need to do base on your individual credit history.  

You pay additional for background, or Court checks, and to download the reports.

Download the landlord tenant laws for the state your property is in..On a month to month notice,, you are required to give notice prior to the end of the month.. 

I've found plenty of sources for home sale prices that I can easily get in a downloadable format (csv) but I can't seem to find a downloadable database of rents vs zip code/neighborhood.