To save or not to save?

[Katie Cooper]

My husband and I have a unique situation: we live and work at a boarding school so our home is currently vacant. We're looking to rent it out but we have an FHA loan, so we need to refinance in order to do so. We're interested in rental property investing and thought we'd start with our own home.

My question is: should we use the income to pay off our mortgage asap? (We're currently putting 100% of my income toward our mortgage and would add the supplemental income, as well). Or, should we put that money in a business account and use it toward a downpayment on a duplex, triplex, etc? When we refinance, should we do non-cash out or cash-out?

We're new to this and have just finished reading Brandon Turner's book, "The Book on Rental Property Investing" which is how I heard of this forum.  We're just getting into this and would appreciate any feedback. Thank you in advance!