mashiara, someone else actually pm'd me this same question. As far as infidelity books and books to help the marriage, I have some suggestions, and FixYou and Obliquestrat's suggestions are good ones. As far as individually, I think that is something that depends very much on each individual. I can suggest some books that I think are incredible; but I come from a dysfunctional FOO and had codependency modeled to me from an early age. Here are the books I loved.
Not Just Friends, by Shirley Glass
For reestablishing intimacy as a couple later in the journey:
Hold Me Tight, By Sue Johnson
7 Love Languages
For me, if I had to choose one it would be Changing Course by Claudia Black. Followed closely by Healing the Shame That Binds You by John Bradshaw and Codependency No More.
I have seen books by Brene Brown suggested a lot too, for women in particular.
I got on Amazon and read the summary for the books and then read some of the comments people leave, it will give you an idea of who it worked for and who it didn't.