Your questions touch upon several areas, so I’m not sure what to address. Most of the choices you make once you own a rental property are obvious–pick tenants carefully, learn all you can about maintenance & landlord-tenant law, keep good records, etc.
I’d add an often-overlooked rule: think long-term rather than short-term in all your decision making. That will often force you to take less profit now for a much greater gain later on. For example:
1. Don’t scrimp on maintenance, especially when turnover occurs. You’ll attract a better tenant, somewhat higher rent, and a higher price when you sell.
2. Pick a neighborhood with a good future and good demographics over one with problems and seemingly better cash flow.
3. Spend time before investing reading up on what you are getting into, talking to other landlords, penciling out “what if” scenarios with various alternative investments. Write down your assumptions and projections and save them. Revisit them in a few years and have a good laugh.
Other items: minimize the down-time of vacancies in every way possible–it will absolutely kill your profitability. For example, when a vacancy approaches, know in advance what it needs for fixup, line up the materials and any workers, go into overdrive to get it perfect and on the market fast. Blitz Craigslist with carefully worded ads and pictures, prepare to show at a moment’s notice. If not rented quickly after several showings, your rent is too high.
A lot of new landlords are buying for cash because non-owner occupied loans are such a hassle and come with a discriminatory interest rate (and because buyers get a far better purchase price with cash). Another route is to buy a rental property as a homeowner with today’s fabulous interest rates, move in for a while, then rent it out. Our Piggs that are agents or brokers can give you more advice about that approach.
