Quote from @Nicholas Klaene: Hello,I'm currently looking to buy my first rental.

I don't remember exactly, but its on top of my 2-car garage, so 20 ft by 22 ft maybe?

My return has been 24%.

My brother lives above.3.  2007 house just updated by owner.4.  

So it was clean and ready for my move in.

Given my response I already gave, what advice do you have?

For my personal portfolio I use a modified spreadsheet amortization by VERTEX, available in Google Docs.  

It's my way of processing.

.: Wild idea based on a property in my local market.

My recommendation would be to choose potential markets - in several price points - that have strong rental demand and year-over-year rent increases and that also are in markets that are appreciating.