The teachings of the Catholic Church on the sacrament of the Eucharist might be summarized in the following points:

• The Eucharist is the heart and the summit of the Church's life, for in it Christ associates his Church and all her members with his sacrifice of praise and thanksgiving offered once for all on the cross to his Father; by this sacrifice he pours out the graces of salvation on his Body which is the Church. (CCC 1407).
• The Eucharistic celebration always includes: the proclamation of the Word of God; thanksgiving to God the Father for all his benefits, above all the gift of his Son; the consecration of bread and wine; and participation in the liturgical banquet by receiving the Lord's body and blood. These elements constitute one single act of worship (1408).
• It is Christ himself, the eternal high priest of the New Covenant who, acting through the ministry of the priests, offers the Eucharistic sacrifice. And it is the same Christ, really present under the species of bread and wine, who is the offering of the Eucharistic sacrifice (1410)

Recommended Reading

• Read the Catechism of the Catholic Church, #1322-1419 (Link)
• Check out Michael Himes' "Eucharist" in The Mystery of Faith for an inspiring theological overview of Eucharist as covenant (PDF).
• You might find interesting Jon Stotts's response to an RCIA question about the real presence of Christ in the Eucharist (Link)
• Confused about transubstantiation? Read Herbert McCabe O.P.'s "Eucharistic Change" in God, Christ, and Us (PDF) 

Because they were Jews, many early Christians drew on Jewish prayer forms for their private and public rituals and prayers. One of the most common formulas, the  berekhah, could be used in a variety of places and settings to recognize God as the creator and sustainer of all good things. Creating a berekhah involves three simple steps:

1. Address God
2. Remember, with gratitude, what God has done or has promised to do.
3. Ask God to do something new. 

Catholics use this prayer formula throughout our liturgies. One clear example occurs right before the Eucharistic prayer, while the priest is preparing the bread and wine for consecration. To prepare the bread, he prays:

Blessed are you, Lord God of all creation, for through your goodness we have received the bread we offer you: fruit of the earth and work of human hands, it will become for us the bread of life.

And to prepare the wine, he prays:

Blessed are you, Lord God of all creation, for through your goodness we have received the wine we offer you: fruit of the vine and work of human hands, it will become our spiritual drink.

The pattern continues throughout the Eucharistic prayer. The priest, speaking on our behalf, addresses God, remembers all the ways that God has acted to save us, and petitions God to continue to save us -- and God indeed does so. 

To live out our own priestly vocations as baptized Christians, we can use the same prayer form to recognize and bless various things in our everyday lives. 

• Take a minute and think of an important task or goal that's in front of you. What do you need to accomplish this goal successfully? (Example: "To get through the day, I need be patient with my children" or "To finish this project, I need to ignore all these other distractions."
• Take another minute to think of an example of how God enabled someone to accomplish something similar. The example can come from the Scriptures, or you can take it from your own experience. For example, God helped Jesus to be patient when none of his disciples could understand who he was or what he was trying to accomplish. Or God helped Noah to build the ark according to specifications, even when there were plenty of other things he could have been doing.
• Take a final minute and compose your berekhah. Address God with a title or name that's meaningful to you. Remind God, with gratitude, of your example, how God helped some folks in some specific ways. And then ask God to help you in a similar way.
  
  Examples:
  
  Father, you helped Jesus to be patient when no one understood him. Please help me to be patient as I try not to burn this lunch while my baby and my 2 year old are screaming for my attention. Amen.
  
  God, you gave Noah the strength of mind to accomplish the task you set before him. Knowing that you've given me my own work to do, I ask you to help me to avoid these distractions and get it done. Amen.