You give the tenant a bar code that allows the cashier to pull up their ledger and prints them a rental receipt.  

USA.com for zip code statistics and also areavibes.comAreavibes can be a bit all over the place sometimes though...

You want someone who knows investing and knows strategies and options- who doesn't just KNOW code 1031 but knows every weird detail of it and creative ways QI's have been able to apply it.

Each new mayor promises to come in and clean it up like every new regime at the federal level promises to clean up the tax code.  

Have a lock box on vacant units so you can give them the code to enter the unit.

 :)  As @Richard C. mentions, your state has codes in place that cover due dates and when a payment is considered late, for all consumer payments not just rent.

You need to find high stressed sellers :   delinquent taxes, code violations, devorce, evictions..

The biggest differentiator  for class property is LOCATION, History  and Reputation on the ZIP code.

California Civil Code Section 1927 provides all tenants with the Warranty of Quiet Enjoyment.

-I can do web design and a little bit of coding.