Infidelity and Forgiveness guidance My husband cheated on me after 3 years of marriage.  I've decided to stay for all the other things he is and does.  Buddhism has helped in all other facets in my life. What would the Buddha advise me to do, what tools would he suggest in overcoming the betrayal of trust, the lying and find my way back to a happy partnership with someone I believe deserves the forgiveness.  I no longer want to speak to him in a way which I feel that is punishing for his transgression.  Please help.
According to the Buddha, confessing one's misdeed, seeing the fault and blameworthiness in that misdeed, and resolving not to transgress again is considered a maturing, a growth in a person. So too is the ability to accept that confession, forgive the person and harbour no malice. 

I hope your husband understands the hurt he has caused you after making a solemn vow of fidelity, and that he has resolved to never do that again.

Now that you have decided to continue stay married, the Dhamma would tell us to let go of thoughts such as 'he cheated on me, he lied to me, he betrayed me'. For holding on to such thoughts will not allow you to find peace and move forward. Re Dhammapada verses 3 and 4.

I did a search on Google a little while ago and according to the results the estimate is that 30% of married men will. Ofcourse the results will vary based on location. I am currently in Sydney. 

Also some studies have shown that 1 in 4 or even 1 in 3 marriages end in divorce. 

So relationships are risky business, but they can be rewarding too. People make mistakes. However having the maturity to, admit the mistake, have the insight to see the error in it, and forgive and continue to move forward together lovingly is the Buddhist way, but it takes two. 

If one party is continually failing to hold up their part, the Buddha says it's better to live alone, our find suitable companions. Also even in relationships we are adviced to practice being an island unto ourselves. For all meetings end in parting.

I recall watching a talk by Ajhan Brahm on this topic some time ago. Perhaps you might find that useful.

No matter what you do, don't live in regret and with thoughts of anger.

In addition you will find it useful developing the practice of the 5 daily recollections recommended by the Buddha. 

http://www.accesstoinsight.org/tipitaka/an/an05/an05.057.than.html

I wish you well.