Teaching sacraments is very important in the education of young Catholics. Many new catechists aren't sure how to prepare their students when faced with teaching the sacraments for the first time. However, with love and patience, it isn't very hard.
First of all, think about the values we hold in the sacraments (mainly reconciliation and communion). For reconciliation, we hold forgiveness, acceptance, love, giving, and a number of other things. In preparation for this sacrament, you should first communicate these values to the students. For communion, we hold self-sacrifice, sharing, community, and more.
When teaching reconciliation, start with how the values apply in everyday life. Talk about friendship and love, and doing good things for the people we love. Invite the children to share stories when they did something nice for someone, or when someone did something nice for them. Mention God's love, and the good things He does for us.
Then, talk about making good choices. Ask the children when they made a good choice and it helped someone. Ask them when they made a bad choice, and how it might have hurt someone. Mention that our conscience helps us decide what's good and bad. Skits or other activities are also really good when talking about choices. Explain how God helps us make good choices.
Read the students the Ten Commandments. Explain how each one applies to them, or people they may know (a good way to explain "Thou shall not commit adultery" is by saying "It means when you're married but you go on a date with someone else"). Plan an activity that relates to real life (a series of skits, maybe a community project) to help them understand what the Commandments mean to them. Explain why God gave us these commandments.
Then, talk about forgiveness. Ask them what they do when they've done something wrong. Explain why forgiveness is important. Then, talk about how God forgives sins (remember that they won't know what sins are, and explain them by saying "A sin is when you know make a bad choice on purpose"), specifically through reconciliation.
Expect the children to have a lot of questions. They will wonder why you have to talk to the priest, if the priest will be mad at them, what they're supposed to tell the priest (children this age don't always have a firm sense of right and wrong, as far as abstract things -- like accidentally hurting a friend -- go). They may wonder how long they're supposed to be in confessional, what happens if they forget their prayers (teach the Act of Contrition around this time), and any number of other things. Set aside plenty of time just to answer the childrens' questions. They need your love and support as they prepare for this. If they're extremely worried, have them play "pretend" about the confession. Choose an adult to pretend to be the priest, and let them have a dry run at it. Some children will want this "rehearsal."
As it comes time for the sacrament, continue to talk about love, forgiveness, friendship, sins, and choices, and how they're all related. Work on the prayers and continue to answer the students' questions. Reassure them that everything will go well.
When the students perform the sacrament, make sure the environment is calm and soothing (as much as you have control over it), and be sure to be near by. Many churches invite families in so that the children have that support. If your church doesn't do that, encourage them to start.
When it's time to teach communion, start reading to the kids from the Bible. Read the story of the Last Supper, and point out how the priests paraphrase this story at every mass. If the children have mass books, invite them to read the Eucharistic mass along with you. If they don't, explain it. Explain how special it is to be able to come up to the front of the church and receive communion with the rest of the community. Emphasize how grown-up and special this is.
Explain the symbolism of the bread and wine (children this age have a hard time with symbolism). Find pictures in their books or anywhere you can of the host, so that the children can see. Answer their questions about all of this. You will often get "Does the bread taste bad?" "Do I have to drink the wine?" "What if I forget what to say or how to hold my hands?" "What am I supposed to wear?" and more.
Teach the children very carefully about the parts of the mass. They will be the major celebrants the day they make their first communion. They will process into the church, singing and possibly doing a special presentation. Often times, they do the readings, the prayers, and everything. This is THEIR mass, and they must know what to do.
If you know what songs they'll be using, teach them the songs early. Talk about when each song is sung (processional, Agnus Dei, presentation of the gifts, Sanctus, Lamb of God, Eucharist, ending processional, etc.). If your church sings anything in Latin or Greek, explain what the words mean.
The children will practice this at the church. Make sure you assign them a seat, a place in the processional, and you allow them to approach the altar and pretend to receive communion a couple of times. The more certain they are of what they're doing, the more relaxed they'll be when it comes time.
Continue to talk about the parts of the mass, and how special it is to be a part of the community. Make sure the children understand that Jesus died for us, and that he gave us his body and blood so that our sins can be forgiven. Do activities to explain what a big deal this is, and what a great sacrifice Jesus made.
On the day of the sacrament, make sure all of the children arrive early, dressed. Line them up, help any readers or soloists rehearse their parts one more time. Coach them on what to do, and reassure them that they'll be great. During the sacrament, be ready to help them out with a quiet reminder should they forget any of the parts of the mass or anything else.
Teaching the sacraments is a very wonderful thing. Get involved with your students and show them God's love by the way you teach them. They learn best by example, and your presence and support are the most important of anything they'll learn this year.