Prospective tenants aren't very discerning regarding the units; due to the lack of supply they are just happy to get a place in town (affluent area, not a lot of lower income rentals.)I have contacted all the buildings inquiring about rents, so I am generally aware of how much they bring in and what their mix is.

What makes discernment difficult is the age of our buildings (100+ years old with unusual building methods, etc.)Thanks so very much for this advice.

Once you've done a deal you'll be able to discern the good deals from the bad deals more easily. 

What questions would you recommend asking in order to discern this at this stage?

Ostensibly, s/he would be doing this to justify a higher valuation and may not be as discerning with tenant selection as you might desire.  

I don't seem to have the wisdom I need to discern what is the best route to take.

This is an expensive market so a new investor has to be very discerning when looking for deals, especially if you are new to the business.

I suspect anyone who has followed his program to get out of debt (including or sans mortgage) has probably, over the course of the journey, developed the financial skills and discernment to make reasonable leveraged real estate investments.  

You can also discern the difference between a good and bad contractor once you get a big business going.

@Brandon C. sounds like you have the gift of discernment ...