The Chaplet of the Seven Sorrows

This devotion goes back to the Middle Ages but has gained new popularity following the Church-approved Marian apparitions in Kibeho, Rwanda in the 1980s. In her apparitions, Our Lady of Kibeho recommended that people pray the Chaplet (or Rosary) of the Seven Sorrows to obtain the favor of repentance.
Father Leszek Czelusniak, MIC, who is in charge of the Marian mission in Rwanda, interviewed Nathalie, one of the visionaries of Kibeho and asked her to summarize the messages of Mary. Here was Nathalie's response:
"The Holy Virgin insisted on the need for prayer. She said that the world is bad. It is necessary to pray, to pray, to pray a lot for this world that is bad, to pray for sinners, to pray for their conversion. She insisted a lot on the need for conversion: Convert to God! Convert to God! Convert to God! While saying that people don't respect God's commands, that people have a hard heart, she also asked us to meditate on the mysteries of the Rosary and to recite it every day. She also taught us the Rosary of the Seven Sorrows. She asked us to pray it every Tuesday and Friday. She asked us to obey the Church, to love God in truth, and to love our neighbor in humility and simplicity. She spoke of the need for mortification, a spirit of penitence and sacrifice. She also spoke of the need for suffering, to bear our sufferings every day. She said that no one enters heaven without suffering. She also told us that acts of charity for the poor make us beautiful flowers that God likes. She wanted a chapel to be constructed here in Kibeho, so everyone would remember her visit and pray for the Church and religious. Holy Mary spoke to us in Kinyarwanda [the language of Rwanda] with her very soft voice."
As for the Chaplet of the Seven Sorrows, it reminds us that Mary plays a key role in our Redemption and that she suffered along with her Son Jesus to save us. It is prayed using a special rosary comprised of seven "decades" containing seven beads each.
Here is how the Chaplet of Seven Sorrows is prayed:
Each group of seven is begun with an Our Father, as in the regular Rosary. Some people start with an Act of Contrition, since the devotion has a penitential aspect. Also like the regular Rosary, the groups of seven Hail Marys are an occasion for meditation on "Mysteries" — in this case, the Seven Sorrows of Mary, listed below:
The First Sorrow
The Prophecy of Simeon
Reading: Luke 2:25-35.
When Mary and Joseph present the infant Jesus in the temple, Simeon predicts that a "sword" (of sorrow) will pierce Mary's soul.
The Second Sorrow
The flight into Egypt
Reading: Matthew 2:13-15.
When King Herod orders the death of all male children age two or younger, Mary and Joseph flee to Egypt with the infant Jesus.
The Third Sorrow
The Child Jesus Lost in the Temple
Reading: Luke 2: 41-50.
Mary and Joseph search for the child Jesus for three days, finding Him at last — after agonizing sorrow — in the temple.
The Fourth Sorrow
Mary meets Jesus carrying the cross
Reading: Luke 23: 27-29.
As Jesus makes His way to Calvary, condemned to crucifixion, He meets His mother, Mary. He is bruised, derided, cursed and defiled and her sorrow is absolute as Jesus drags His own cross up the hill of His crucifixion.
The Fifth Sorrow
Mary at the foot of the cross
Reading: John 19: 25-30.
Mary stands near her dying Son unable to minister to him as He cries "I thirst." She hears Him promise heaven to a thief and forgive His enemies. His last words, "Behold your mother," charge us to look on Mary as our mother.
The Sixth Sorrow
Mary receives the body of Jesus
Reading: Psalm 130.
Jesus is taken down from the cross and His body is placed in Mary's arms. The passion and death are over, but for His mother, grief continues. She holds His body in her arms.
The Seventh Sorrow
Mary witnesses the burial of Jesus
Reading: Luke 23: 50-56.
The body of Jesus is laid in the tomb. The most tragic day in history ends, Mary alone in sorrow, awaiting the Resurrection.
http://marian.org/mary/prayers/sorrows.php