This was my first time looking for information on Salem Plantation. Haven't heard of Salem plantation? You're not alone. I had only heard rumors of slaveholding in Salem, Connecticut. Maps seemed a good way to start, since they should show me the layout of the farms. Of course, as it turns, the maps don't exist. The plantation had almost disappeared by the early 19th century.
However, I found something a little better. In 2002, the Hartford Courant ran a complete description of Salem plantation. It's not a map, but it is a start.