Forgiveness is not easy. It can be painful. Actually, from God's perspective, forgiveness had a great price..the death of His one and only Son. But our forgiveness towards another human being doesn't cost us our lives. It may cost us our pride, giving up retribution towards them and the loss of personal belongings. Certainly, you can forgive someone for past offenses but still hold him or her accountable for present responsibilities. Here are some guidelines and scriptures which will help you as you consider forgiving someone and letting go of the past hurts. 

1. Deal constructively with the root cause of anger towards the person... Proverbs 29:11 
a. Ask: What am I angry about? What is my responsibility? What is his or her responsibility? 
b. Forego Retribution: "Do not repay evil for evil . . ." (Romans 12:17-18) "... overcome evil with good." (Romans 12:19-21)
c. Pour out your anger to God & leave it there. (Psalm 10:1-18) 
2. Plan a constructive confrontation (Matthew 18:15) 
a. Apologize, if appropriate (Matthew 7:1-5) 
b. Use a soft, loving approach. Think about how much God loves you & has forgiven you (Ephesians 4:32; Psalm 103: 11-12). 
c. Be honest, yet tactful (Ephesians 4:15,25) 
d. Indicate the behavior change needed 
3. Choose to forgive 
a. Release him or her from guilt & bondage (Ephesians 4:32-5:2) 
b. Let go of your demands on this person 
4. Return good to him or her (Matthew 5:43-46) 
5. Depend on the power of Christ to change your attitude towards the person. (Philippians 4:13) 

Forgiveness is worth it! When all is said and done.....you have to give up the power, the pride, the hurt because you need to be released from the grip of bitterness. And the other person needs your unconditional love. "Love cover a multitude of sins" 1 Peter 4:8 
Then you will discover that "forgiveness is a choice you make based on the forgiveness you have already received in Christ."

Read more about how to know God personally in the article on Faith.
Read more on forgiveness: The Power of Forgiveness or 
What Makes Forgiveness so Hard Order:
The Healing Power of Forgiveness by Dr. Ray Pritchard  
Order the What's Good About Anger? anger management certificate course This book and program teaches you how to turn your anger into faith, assertiveness, problem-solving and forgiveness!
Check out the Resources page for books like this:
To Forgive is Human : How to Put Your Past in the Past by Michael E. McCullough, Everett L. Worthington (Contributor), Steven Sandage (Contributor)
The Freedom & Power of Forgiveness by John MacArthur $13.99