The best marriage manual ever written is the Holy Bible. It is absolutely filled with wisdom that will help your marriage. For instance, I Peter 3:7 says, "Husbands, treat your wives with courtesy and respect so that your prayers will not go unanswered."
If you meditate on that long enough, you will realize that you should try to treat your spouse with courtesy and respect every minute of every day. Then you can expect the quality of your marriage to improve.
Communication will improve because you do not have many negative emotions. Negative emotions are a barrier to communication. Your sex life will improve for the same reason and also because you want to be kinder to each other. In many cases your income will increase because you do not have so many negative emotions that make you work inefficiently.
Get in the habit of reading two pages of the Old Testament and two pages of the New Testament out loud together every day. Alternate paragraphs so that you are forced to pay attention. Just watch the quality of your marriage rise.
Male sexuality is about the weirdest thing that God ever invented.
Ladies, you must understand that men need it. It is your responsibility to make sure he is not too frustrated. Just assume that it is impossible to have a happy marriage unless your husband is satisfied with his sex life.
And men, part of the equation for having an excellent sex life is to treat your wife with courtesy and respect every minute of every day.
Men, you must understand that women need it. In our culture, the men are usually responsible for making sure the household earns enough money. Security is incredibly important to the wives, men.