All tenant files and unit keys are kept in a secure area, locked.We enter financial data from bank statements/check carbons, credit cards statements and mortgage statements into Quicken and print out financial reports for our tax professional as needed.

I too never use assessments for my purposes, since real valuation data is available.  

I like the idea; everyone will ask, "Where did you get the data?"

I would add the tax-free sale data to the mix on your sale question.  

I see lots of folks showing up at auctions holding the news paper so either way works..And if you don't want to pay for a newspaper ... then you hop in the car and go to the court house and Pull the NOD's  some court houses are friendlier than others with access to their data

My idea is that the CPU could upload routine logging data to me maybe a couple of times a day, and send me a text message for alerts (water running for a long time, temperature falling near freezing). 

@Samuel SedoreI see 2-4 unit properties (even 5 or 6 units in many cases) as really being residential properties and you are frequently dealing with unsophisticated vendors and real estate agents whose bread & butter is selling pretty houses to Dick & Jane and who have no experience in how to sell to an investor.When you step into small multiunit apartments (say 6 - 30 units), my biggest frustration is the number of vendors/agents who bring a property to market as they would an SFR, rather than taking the time to prepare a memorandum of offering and a professional package comprising financial (2-3+ years), operational & marketing data, service contracts, etc.   

Using his marketing funds, I will do the grunt work to drive the neighborhoods, collect the data (addresses and home owners name), send out the marketing on schedule, take the calls, set appts and get contracts signed.

You'll then have to have the data converted from ASCII to excel or something user friendly.  

I also found neighborhoodscout.com has anyone used that data successfully to help determine what neighborhood to buy in?