Confused on best route to take.......

[Matthew Palanek]

I am not sure the best way to go about this......but here is my situation & plan

I am buying a duplex for $160,000 soon. Charging 800/mo for my tenant and ill be putting 800/mo for my "rent" in an account to save. After 1 year, I will have about $15,000 in equity. So is it better to take out a second mortgage or refinance? After my 1st home, will I have to put 20% down or can I put less? Basically, after I have my first home, what is the quickest & cheapest way to get to 5 homes? Thanks for any replies!