I know school districts are a big indicator and have also read about looking at the city planning website for future developments...but not sure what to look for specifically. 

Web site should give you some insight too.

During the year rented, bottom line was ~8k in the positive.

An overview can be found here.The CMHC web-site also has a mortgage calculator which will accommodate high-ratio, insured mortgages.My recommendation is to learn the underlaying principals, be able to perform the calculations manually and develop your own spreadsheet.  

To be specific, my steps to fully get into this world so far have been: Buy my first home Sign up to BiggerPockets website Listen to the first 5 podcasts (loving it)Send this messageEvaluate specialized Masters in R.E and meet with alumni and teachers plus attend one class as a guest observerMeet with friends working in the industry (mainly working for big Funds and Developers)Bought the 13 most widely recommended books in R.E.

Why would someone put up a duplex for sale if it is cash flow positive?

I'd recommend going to the county website of the property that you're interested in.

@Jaire A Ruffin I would just look around the BP website.

You would be able to sell off your position to the new buyer (plus your added value), which you may find to be very difficult; essentially acting as a wholesaler, but with tighter parameters (i.e. a buyer who's willing to do seller financing within the owners boundaries).

On the other hand, what most don't understand is although the LTR may be cash flowing in your eyes - it may not be a positive number to the lenders underwriter depending on what expenses, etc. are shown on schedule E.