I use Zillow Rental Manager to collect rent electronically, I just started using Stessa to track data, a Excel check book register to track expenses and deposits and TurboTenant to list my vacant properties.  

I'm primarily on VRBO and I get these regular suggestions from VRBO that state "adjust your rate based on changing market data". 

Once we have historical data to lean on it becomes easier to provide that data.

That means the average home will double in value in 7-10 years.

Can't tell when in the future all of these data points (low interest rates, housing shortage, Builder shortage, Lot shortage, migrating investors, migration from city to country, family RE knowledge) will come together.The process of subdividing created value from $6,000 farm ground per acre to $50,000 per acre for the 2 acre lots. 

These 15 year mortgages are dwindling down fast and if it appreciates at least 5%/year I’m doing cart wheels and back flips as I watch my properties go up in value.

The property data can be obtained through you local assessor's office. 

Companies like listsource.com (there are less expensive options) specialize in providing that data if I’m not mistaken.

Meaning, if it improved $50k in value but took $100k to get there, is that worth it?  

Like everyone else in this thread has said, your construction background will be invaluable!