I turn to them to list the rental, which just means another form of payment for them. 

I went on Zillow and found this 1900 square foot house with 2 bed, 1 bath and a nice floorplan in the listing.

You may also have to pay a broker to rent it, when usually the tenants cover that during peak rental season (May-July for 9/1 leases).Good thing is once it's rented you should almost never have vacancy if you're mindful of re-listing it in a timely fashion.

Perhaps take a look at:  https://www.loopnet.com/ and see which types of commercial lease listings interest you and from there take inventory of which brokerage and listing agents are prominently features in the space that interests you.

Rpdata.com.au is probably the best for residential dataAny of the major agencies CBRE/JLL/Knight Frank/Savills/Mirvac will have reportsPlus a lot of the publicly listed REITs will have reports too ie DEXUS/Investa/Lend Lease/Westfield/Stockland/Cromwell etc.

I recently purchased a 1500 SF two-story rowhouse in New York with a building class designation of Two Family Dwellings - Brick (B1). My partners and I subdivided the property into two distinct rental units:
Unit 1: ...

Do I start looking into new properties now before I list it to sell?

If not, re-check everything - listing, photos, rates, booking policies, etc.Often, newbies have rates that are too high and/or booking policies that are far too onerous.

To get a full picture, there are many, many questions you need to know the answer to, and this is only a partial list.

@Lance Wakefield since you are in Collin County, if you plan on attending the Collin county sale; check with the Collin County Sheriff for property listings.