I read "Torn Asunder." I did not finish it, but there was some helpful information and a bit different than other books I'd read. I recommend "Beyond Affairs" by James and Peggy Vaughn, followed by The Monogamy Myth." Peggy's website is DearPeggy.com - Extramarital Affairs Resource Center and she has a lot of articles and help, there. Peggy and James are experts on affairs, having survived them, as well.
P.S. You may also like my blog, "After His Affair"