Advice Needed: First-timers, buying with cash

[Eva Jensen]

Greetings! My husband and I want to using a windfall to buy duplexes or single unit rental properties for passive income.  Is it better to pay cash for one or two properties, or get financing for three+ properties? The logic here is that we'd only have enough cash to buy 1-2 fully. But alternatively, we'd be able to acquire 3+ properties if we got them financed w. a large down payment...  
Some have advised us that if we do the mortgage route with big down payments on 3+ properties, we'd get more passive income (because more properties). But others have advised that it's better to buy one or two in cash and "be the bank" to flip in a couple of years instead of piling up interest with the bank.

Any advice would be coveted! 

Second Question: 
Anyone here with knowledge of rental property investing in southern PA, please contact me.  That is where we are currently living/looking. We are nervous about long distance investing...if anyone can talk us into it, we're listening.  ;) 

Thank you all!!!

[Jim Pellerin]

@Eva Jensen If you buy 1 property with $100,000 cash and it increases by $10,000, you have made a 10% return on your investment. If you buy 2 properties with $50,000 down on each, and finance the other $50,000, and they both increase by $10,000, that's $20,000 return on your $100,000 investment, which is a 20% return on your investment. Just be sure you put enough down so that you have a positive cash flow from your properties. OPM is other people's money. e.g banks, lenders, investors, etc.