This selection will determine the opportunities that will be pursued to get started.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)Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/termshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/perkshttps://www.biggerpockets.com/forums/categorieshttps://www.biggerpockets.com/courses/a-beginners-introduction-to-real-estate-investing (video courses)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/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/?

Your time here will be well spent.Since your interest lies in multifamily units, I added the below links for your review.https://www.biggerpockets.com/renewsblog/2013/04/09/how-to-buy-a-small-multifamily-property/ (How to buy a smail multifamily property)http://www.biggerpockets.com/renewsblog/2014/07/19/how-to-buy-a-duplex/ (guide to buying a duplex) https://www.biggerpockets.com/renewsblog/2015/11/16/how-to-choose-areas-multifamily-deals/ (Choosing multi-family deals)Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/termshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/perkshttps://www.biggerpockets.com/forums/categorieshttps://www.biggerpockets.com/courses/a-beginners-introduction-to-real-estate-investing (video courses)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/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/?

I built a spreadsheet and  I've done a light scrub on 90 units based on Mls data over the last few days.  

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. 

@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/?

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

I'm likely to purchase out-of-state property in 2016 and will travel to ensure that things are in order before making a purchase.  

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. 

Your time here will be well spent.Since you didn't mention an area of interest, I added the below links for the three most popular niches for your to select one or all.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)Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/termshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/perkshttps://www.biggerpockets.com/forums/categorieshttps://www.biggerpockets.com/courses/a-beginners-introduction-to-real-estate-investing (video courses)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/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/?