For buy and hold properties, this means including debt service, taxes, insurance, management, and reserves for vacancy/maintenance/repairs. 

HI Tom,I've done plenty of these on the lender end and investor end as well.If you go the FHA route which is the least down payment option you'll only need 3.5% down and will need to adhere to:- min 3 months cash reserves based on the proposed monthly payment- gross rents on all 4 units X 75% factor must be equal or greater than the total monthly payment of the property (PITIA - I found out this not include HOA in this formula as we had a fourplex with a HOA once too).

I went to the 2 hour seminar, sounded awesome but they just tease you with info, then I signed up for the 3 day ($200), then jumped on BP and read about what a waste of time it would be, and canceled my reservation.

And a 'reserved' sign.

My only comment would be have you confirmed your real estate taxes(Dormont borough, Keystone Oaks SD, school earned income, etc.)?

There are burn marks on the carpet in one of the bedrooms and one of the kids confirmed that her brother way 'playing with fire' -- this scares me. 

Note, your money will have been tied-up this entire time without having access to the home.Look-up "redemption period" to confirm some of these statements.  

I was the high bidder for quite a while and could have stopped bidding below the reserve, but I did not want to lose the property and continued bidding until I hit the reserve.  

You need to make sure to keep reserves!

If you mean a 100+ unit apt complex, $100K will not be enough.You may be able to get a loan for a 25-50 unit complex for $500K with 20% down, assuming you have other capital reserves.