Surviving an Affair by Dr. Willard Harley is really good. He also wrote His Needs, Her Needs. In Surviving an Affair, he says that reconciliation is not possible while the affair is going on. You have to make sure you are not the cause of your spouse's unhappiness, disrespect, etc. All, or at least most, affairs, die a natural death. As long as you have treated your spouse like a friend, when the affair ends, most spouses do want to reconcile.
Avoiding the Greener Grass Syndrome by Nancy Anderson is also a good book.
