I've shared some of my favorites below in an effort to provide an initial filter for you.This thread contains a healthy discussion on the merits of various multifamily training programs:https://www.biggerpockets.com/forums/432/topics/40...Here are some great book recommendations on multifamily investing that should help deepen your understanding of the domain:https://www.biggerpockets.com/forums/432/topics/40...Here are some great podcasts that cover multifamily investing.  

I also am researching new construction for multifamily, specifically with green / healthy building materials.

What are some areas/zip codes having more this kind of inventories but still have healthy amount of demand to support the supply?

A mix of both is healthy for most of us (more flips until you get a war chest).For my situation, I like to think of every property I rehab or own as being for rent or sale (even though I plan for 1 option originally). 

Healthy networking and well wishes to you on your REI endeavors.Kudos,Mary

Have a happy, healthy and prosperous New Year.

Assuming a property has been purchased at a good price and the month to month cash flow is healthy, the two most likely scenarios that will put a property at risk are:1) A huge capital expense that arises (ie replacing an HVAC or roof).To mitigate this one should save at least 10% of gross income and set that aside for major future repairs.

Healthy networking, prosperous investing and happy new year to you.Kudos,Mary

After 7 years of steady rentals we sold it to a fellow investor (who was aware of all the work we did) for a very healthy profit & hold the note @ 12%.On several others it helped knowing what we were into before we make the final offer. 

I will try to be open-minded for a healthy discussion as I hope others will be.