In reading through these responses, some of them give great solutions and things to think about, and some of them are flabberghasting and full of false information.

I've been reviewing the Bexar County Clerk's website, and man...I just can't tell if they've been repaid, cancelled, extinguished etc. 

Are there any good materials (books, websites, etc.) you might recommend? 

Searching the Local GIS and county websites.

Searching the Local GIS and county websites.

The reason you have so many people in this thread calling out what you said is because of how obvious it is that you are spreading false information in a thinly veiled attempt to generate leads for your PM, sales, rehab, marketing, everything.

They claim to work with several banks, investors etc. their website platform and BPO appears legit.  

I’ve seen a few websites about seminars/training, while google searching but then see reviews that aren’t so great.

I received immediate, good response to my marketing on the rental websites available at that time. 

If you read about transfer taxes at the PA Dept of Revenue website, you should be able to find a document with a table where you would look up that factor.