I would HIGHLY recommend Mary Enig's book, "Know Your Fats", if you're interested in understandng the role that fats (saturated, mono- and polyunsaturated, transfats) play in our bodies and the foods that we eat.

She gives an in-depth discussion about the dangers of transfats. Also discusses the rapid decline in general public health since tropical oils and saturated fats have been removed from our foods by the political lobbyists from the edible oils industry. It's a very informative read.