I just looked online and saw that in Seattle for months to month lease the landlord is only required to give 20 day notice.

Go to Etsy and search for "rental property tracker," and you will find hundreds of nice spreadsheets to track 10-20 rentals, usually for under $10.Software has extremely helpful features like online payments, marketing syndication (click a button, and your property is advertised on multiple sites), electronic document review/signing, maintenance tracking, and owner reports.

In my experience, most of the online calculators are just taking an educated guess for you.

Is the information about “In MA, tenants generally have 30 days to pay repair costs...” available somewhere online? 

The use of online classes has been increasing every year and are projected to continue to increase.

check the local municipal code, most are online.

It seems you are falling for the alarmist rhetoric you’ve been reading and watching online.

You can find different strategies on how to find and reach these folks, such as driving for dollars, targeting mailing lists, networking with Realtors and other wholesalers, and having an online presence, plus paid social media ads, etc.

But i guess in today's world where things are on line and investors are used to Internet communications this is much easier than those days.

I’ve got that Arizona license #AZ-21837, and I lean on a pretty wide network of top-tier realtors and boots-on-the-ground pros who can give you insights you might not find by just browsing listings online.