Or you can visit the local jurisdiction's courthouse website or physically go to the courthouse to look up liens.

The approach I would take is to get some comparable 2-5 sold recent and 1-2 listings in close proximity as possible.  

Of course physically segregating them is cleaner, but may be costly.  

I am actually not too far from where you live, so I assume you do not have a physical presence often in Memphis.

Ask to see his license numbers and his insurance documents and then call to verify they are real and in good standing.Assuming you don't fire him, ask him to describe his training and experience so far and check his references from past jobs completed.Then ask who exactly will be coming to your home for each job to be performed.Who will be physically doing the painting,flooring,etc.Before work commences,ask him to show you the invoices for all materials purchased with your money and then visually verify that all the materials arrived to the job site and are not sitting in his cousins garage waiting to be used on another persons job site at your expense( theft of materials is all to common).Don't let him buy 100 gallons of paint and then only use 65 gallons and keep the rest for himself,see if it can be returned for a refund.The same with laminate flooring,carpet,bricks,pipes,and other materials bought in bulk from wholesalers.At each step,bring in an expert to inspect the work completed to see if he screwed it up and it need to be redone at his expense,not yours!!!

I like the proximity to a station that you can load onto or off on public transportation.

As far as creating your SOP, remember that you have to get out in the field and physically view properties to truly learn about the local market and figure out what your niche will be.

I am also in Northern VA and am curious what made that market appeal to you, other than just prices and proximity to NOVA. 

Because of my current work situation I am never in any one physical location for more than 4-6 weeks.  

There are a lot of other things to consider besides the time they physically spent at your house doing the work.