Review their online financials/annual statements.

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.

The majority of buyers appreciate the expertise that a good agent provides (local market knowledge that can only be gained by being active in the market buying and selling all the time, looking at most of the new listings in person or at least online daily, a background in or at least understanding of building construction, relationships within the network of professionals in the industry doing deals, vendor referrals, legal protection through E&O insurance and keeping up with constant changes in approved contracts and required disclosures and forms, negotiating skills (the average person is terrible at negotiating directly and has no desire to, I find Americans are uniquely averse to negotiating and prefer to outsource it but I digress), etc.).

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

Ditch FM radio, and/or sport radio, and start in hard on the podcasts. 

Making money is a team sport. 

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

Study other investors winning strategy the same you would study a sports teams winnings.