Finally, the strategy of turning your primary into a rental and purchasing another primary works best when the market is tanking, not when it is hot ... then in 2 years and change if/when the market recovers, you can sell your 1st tax free, or keep as a rental if you prefer at that time ... buy low, then sell high rather than sell high, buy high (or sell low, buy low) like most people do. 

IMO and experience the 50% rule is overly conservative - - I use 30% of GSI as a boundary to determine if the property is being managed properly - - lower indicates inaccurate data and higher indicates obsolete fixtures and equipment.

You're still handling every line as three data points. 

Finally, always treat everyone as you would like to be treated and you should not have any problems. 

@Danielle J.Welcome to BiggerPockets, a place to interact with a vibrant REI group, learn the real estate business and language.Since you did not mention a specific area of interest, I added links to three of the most popular niches for your to select one or all while you wait for local networking contacts.http://www.biggerpockets.com/renewsblog/2013/02/22/buying-rental-property/ (how to buy a rental property) http://www.biggerpockets.com/renewsblog/2014/01/07/flipping-houses/ (step by step guide to flips)https://www.biggerpockets.com/renewsblog/2015/01/31/ultimate-beginners-guide-real-estate-wholesaling-2/ (Ultimate beginners guide to wholesaling)It doesn't matter if you are young or old, totally new or need to build upon your experience.Yes, you have just announced a commitment to the thousands in this community about your seriousness regarding REI and have taken this bold step to affirm it.Your time on this site with the BiggerPockets community will be well spent and can be financially rewarding if you so desire.Don't get overwhelmed by the massive amount of data archived on this site.Simply, bone up on the areas that you need to expand knowledge in such as, Forums, Marketplace, Learn, Network, Analyze and Resources.Feast on the Podcasts, #askbp Podcasts, blogs and webinars REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/ (7 absolute must read books for beginner REIs)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?

And after a couple of offers, the light finally came on.  

How do I go about choosing the right city and what data sources do I take advantage of in making this decisions?

I have looked at the "city-data" website for Yonkers, NY and I know that the population increased 9% since 2000 and the median income is in the $50,000 range. 

FINALLY!

Perhaps you may want to speak with a realtor about viewing REOS on the MLS.You can't view them (legally) prior to auction, and they are no longer owner occupied if final judgment has been obtained already.