Come to me, all you who labor and are burdened, and I will give you rest. Take my yoke upon you and learn from me, for I am meek and humble of heart; and you will find rest for yourselves. For my yoke is easy, and my burden light.” (Matthew 11:28-30)
In case you need a refresher on how to go to confession:
Before coming to confession
Take time to reflect on your life since your last confession and ask the Holy Spirit to reveal to you any sins in your life (both things you have done, and things you have failed to do). It is quite helpful to use an examination of conscience to go through the 10 Commandments so we become aware of types of sin which we may not think about. Then once you are spiritually prepared go to confession.
When you are in the confessional/before the priest:
1) Begin by making the sign of the cross, saying "In the name of the Father, and of the Son, and of the Holy Spirit... Amen"
2) Then say: "Forgive me Father for I have sinned. It has been ______ (days/weeks/years) since my last confession."
3) Then say what your state of life is in a broad sense (ie/ single / married / religious sister / priest etc.). This helps the priest to better understand the context of your sins and better give counsel and penance.
4) Confess your sins. All Mortal (serious grave sins) must be confessed to the priest. It is important to mention the type of sin and how many times. Then all venial sins (everyday faults) can be mentioned as well. This is not the place to mention other person's sins, only your own. Nor does the priest need stories and tons of background information. Just enough to understand your sin and the context.
5) Once all your sins have been confessed, say: "I am sorry for these and for all the sins I have committed in the past".
6) The priest will then give counsel and may ask for clarifications. He will then assign you a penance to do in reperation for your sins. If the penance is not clear or unrealistic, express that to the priest.
7) The priest will ask you to say your act of contrition. There are various versions you can say. Here is a standard form:
O my God, I am heartily sorry for having offended Thee, and I detest all my sins because of thy just punishments, but most of all because they offend Thee, my God, who art all good and deserving of all my love. I firmly resolve with the help of Thy grace to sin no more and to avoid the near occasion of sin. Amen.
8) The priest will then pray the prayer of absolution, granting you God's forgiveness for your sins. He may then conclude by saying these or similar words: "Your sins have been forgiven, go in peace"
9) You would respond "Thanks be to God." Then you would leave the confessional and carry out your penance as soon as you are able to.
Here are some further resources:
Examination of conscience (These help you look at different categories of sins, and asks questions to help you reflect on your actions and lack of actions).
Read paragraphs 1440 to 1498 in the Catechism of the Catholic Church