There is never an absence of articles, books, magazines and blogs about how to sustain a healthy marriage. Most of the literature on this subject gives couples rather objective commonsense advice that is good on paper, and sometimes bad in reality. I found an article on yahoo.com about what secrets should be kept from your partner in order to maintain a good relationship. Those secrets range from things like "I flirt with co-workers" to "I still think about my ex". While these secrets are hurtful, chances are that if you are doing many of the secret things on the list in the first place, your marriage or relationship may be in trouble anyway. I'm all for keeping the mystery in a relationship, but the key to not ending up in divorce court is respecting your partner and not keeping secrets which could be detrimental to your marriage in the long run. With that being said, I say take all of these relationship self-help articles and books with a grain of salt. They are not always right and sometimes the advice that they give is flat out wrong.
If you would like to read the yahoo article about the Secrets You Should Keep From Your Partner, see: http://health.yahoo.com/experts/menlovesex/40807/5-secrets-you-should-keep-from-your-partner