How to accumulate Buy and Hold properties

[Matt Mach]

I keep reading posts that say "no money down" and "bought in cash", I guess I don't completely understand what those mean so hopefully this post will clarify that. 

I live north of the Boston area, real estate is expensive here. I bought a small condo in 2007 (currently rented but $0 cash flow) and was able to buy a fixer 2 family that we currently live in. Thanks to the market here I probably have about 100k in equity. 

Now I couldn't fathom buying either property in cash, so I don't know how a buy->rehab->refi and cashout approach would work for me. My understanding of how to buy a second property would be to put 25% down and in order to use my rental income I would need 2 years of history (which I have now). 

Best case that I can see right now is, I'm able to pull out enough money for a down payment on a second 2 family in order to buy it and rent it out. At that point, don't I need to wait another 2 years before I am able to display to a bank my correct income to buy a 3rd?