In regards to learning more about real estate and maybe how to answer those questions I'd recommend listening to BiggerPockets (Rookie and Real Estate Podcast), there are also some market specific real estate podcast you can check out depending on the area you want to invest in. 

Check out the website for: American Institute of Certified Tax Planners

I would check your lease to see if there is any language that addresses this.

This is a house that has additional square ft added on, so they listed that as the reason for marking the question as positive, as new foundation and support was added for the additional sqft.My question is: Is it a standard practice to check this box as "yes" in the disclosure when additional square feet has been added on to the property?

Check out RG Property Services :)

Check out my personal favorite, Set For Life by Scott Trench , or The Total Money Makeover by Dave Ramsey.3.

I was pretty sure they weren't vacant, but I checked them out anyway. 

List of things to fix:Clean house, Carpet replacement, Floor patch up, Interior Painting, Bathtub recaulk, water heater replacement, leak check, small dry wall cut and restore, Roof fascia repairThank you.

Secondly, check to see how quickly they update status changes (active to sold,  NOD to Recession, Auction date or postponement). 

Do a lot of research into properties they currently manage and check condition, etc.