3 residential lots for sale, advice on how to research these lots

[Jeff B.]

Came across a guy selling 3 residential lots, curious on what I need to look for and what to ask. New development in this area and will be in prime area of high school middle school. Three prime lots around 14k sq ft per lot. Do I call the city, I'm guessing he has the land deed for these. Any assistance on who I should contact with city to verify etc.