What should I track?

[Brandon Kelly]

I bought a house in 2010 and began renting it in 2015.  I never planned to rent it so I have never really tracked anything financially on the house other than it basically breaks even.  A few months ago I discovered BP which got me interested in real estate investing.  Now I am a couple of weeks away from closing on my second property which I am purchasing as a rental property.  I would like to do it right this time.  Any advice on what I should be tracking financially for the start would be greatly appreciated.