Excerpt from my latest Sasstrology article (please leave comments on the Sasstrology site):
"In synastry, contacts to the natal South Node indicate each person’s involvement in the other’s past, and contacts to the North Node describe the role they can play in the future. This is usually analyzed in the context of person A’s planet aspecting person B’s Node. However, Nodal overlays to the houses are not discussed as often. These overlays are significant, but only under certain conditions."