Some places publish, some don't.Then you need to be a good skip tracer and a good sales person, as you are going to have to convince people to allow you to help them recover the overage, which they could do for free.

Educate yourself and then talk to a syndication attorney like @Kim Lisa TaylorAs for how to find investors I suggest @Matt Faircloth's book from BiggerPockets Publishing Raising Private Capital

That is why Zillow is fairly accurate in some areas where sales data is part of the public record and less accurate in areas where data is not published.

Have a look at BP's blog where new articles are published every day: https://www.biggerpockets.com/blog 4.

I have read/listened to a lot of books on real estate investing and, quite honestly, the books published by Bigger Pockets are fantastic. 

There are probably corresponding discrepancies in appreciation as wellwww.rate.com publishes the avg $/sq ft for many zip codes, but I’m not sure how accurate it is.

I mean that purely from a statistical standpoint and I recently published a blog article about the new roles of an agent in working with buyers and sellers that you might benefit from:  "Why doesn't my agent send me any properties?"

When I got started investing, I wondered why nobody just published the magic "good deal ratio."

If all the other homes in that area are renting for $1650 then that is what they will pay not the amount that is publishedThe published market rent rate is an average of several towns combined in an MSA.

Feel free to send me a direct message.The Real Estate Center at Texas A&M publishes a fantastic Texas Landlord and Tenant's Guide that was invaluable to me when I first became a landlord five years ago.