On the surface, debut novelist Sara Gruen's book "Riding Lessons" is about horses. But so much of her novel new is about interpersonal connections: between parents and children, between lovers old and new, and between humans and animals. Gruen, who lives in Chicago also has a message to convey through her work, and has donated a portion of the proceeds of "Riding Lessons" to two New Hampshire horse and animal rescue farms, one in Northwood and another in Chichester.