As you know, we are well into Holy Week, the holiest time in the Christian calendar. Here is a rough, brief guide to some notable things that are often associated with each day. It is not anywhere in the vicinity of being rigorous or comprehensive.
Palm Sunday
Jesus enters Jerusalem to the shouting and acclamation of many people, who lay palms before him and publically laud him as the Davidic King.
It is the beginning of the end, for the Triumphal Entry initiates the Passion, and sets into motion a chain of events that inexorably lead to betrayal and darkness. There is celebration, but it is the empty celebration of those who will scatter at the sign of trouble; there is joy and truth, but the joy is laced with irony and the truth is not understood.
Great Monday
Palm Sunday began with a false conception of kingship. As Holy Week progresses we begin to understand the true nature of the King of Kings, and the true of nature of His Kingdom. Holy Monday is often associated with the barrenness of the fig tree (Mt 21:18-20).
Great Tuesday
Holy Tuesday is associated with Jesus' exhortations to wise preparation and vigilance (Mt. 25:1-13; Mt. 25:14-30). Something comes this way, a parousia, a glorious appearing. He tries to tell us. We do not understand. But we watch and pray.
Great Wednesday
Holy Wednesday is often associated with repentance (Mt. 26:6-13). Christ's feet are anointed by a repentant woman.
On one tradition on Wednesday evening there is a service of holy unction: the people are blessed with a small anointing of oil, representing the gracious anointing of the Spirit.
But there are darker things afoot. Judas plans a betrayal.
Maundy Thursday
Great and Holy Thursday is associated with four events. The first two occur in the upper room with his disciples. In the first, Jesus washes his disciples' feet -- taking on the role of a servant.
The second event is the Last Supper. It is unclear from the Gospel accounts whether this supper was the Passover. The Synoptics strongly suggest it, but they aren't always careful about chronology. John arguably is, and he explicitly distinguishes it from the Judean Passover. My understanding is that Galileans sometimes celebrated Passover on a different day (e.g., the day before or the day after) the Judean one, so it's possible they are both right. Or, which is also possible, there might be some point we don't know.
Regardless, the Last Supper is the Christian Passover. It is the meal before the cross of blood that will lead the angel of judgment to pass over our houses. It is the conception of the Church, which will be quickened at Pentecost.
Jesus gives his disciples a new commandment:
A new commandment I give to you, that you love one another; even as I have loved you, you also ought to love one another. By this everyone will know that you are my disciples, if you have love for one another.
A high standard: to love each other as Christ loves. This is why the day is often called 'Maundy Thursday'. 'Maundy' comes from 'mandatum', commandment.
After the Last Supper the Agony in the Garden begins. Jesus withdraws to pray, and we come to the next two events.
The third event is the prayer noted by John, often called the Marvelous or High Priestly Prayer.
The fourth event is the betrayal of Jesus by Judas, in which Judas betrays him with a kiss of friendship.
At evening Easter Triduum begins, ending on Sunday evening. The prayers of the Christian year begin to reach their highest tide.
[For an excellent Catholic discussion, see Fr. Neuhaus's comment on Holy Thursday at the First Things blog.]
Good Friday
On Holy Friday Christ dies. Because of this, it is traditional to have no communion on this day; it is common for churches to be decorated in black, taking on the semblance of mourning.
Christ treads the Via Dolorosa from Pilate's Hall to the Golgotha; his route is ritually rehearsed through the Stations of the Cross. The fourteen stations most commonly used today are as follows:
1. The Condemnation. Brought to trial before Pilate, Jesus is condemned to death.
2. The Taking of the Cross. The bar of the cross is laid upon his back.
3. The First Fall. He stumbles under the weight of it.
4. Jesus and His Mother. Along the way to his death Jesus comes face to face with His mother.
5. Simon of Cyrene. A man from the crowd is forced to help carry the cross.
6. The Veronica. A woman uses a cloth to wipe Jesus' face, which is now covered with blood and sweat. By tradition she is called Bernice (or in the West) Veronica, and she is said to be one of the women Jesus had healed (Mt. 9:20-22).
7. The Second Fall. He stumbles again.
8. The Women of Jerusalem. The women of Jerusalem weep for Him as he passes.
9. The Third Fall. He stumbles yet again.
10. The Removal of the Garments. He is stripped of his clothes.
11. The Fixing to the Cross. He is nailed to the cross.
12. The Death of Christ. Seven sayings are associated with the death of Christ, the Seven Last Words of Christ:
Father, forgive them, for they know not what they do. (Luke 23:34)
This day you will be with me in paradise (Luke 23:43)
Woman, behold your son . . .(John 19:26-27)
My God, my God, why have you forsaken me? (Matthew 27:46, Mark 15:34)
I thirst. (John 19:28)
Father into your hands I commit my spirit. (Luke 23:46)
It is finished! (John 19:30)
When Christ's side is pierced, water and blood flows out: baptism.
13. The Deposition. He is taken from the cross.
14. The Tomb. He is laid in the tomb of a rich man, Joseph of Arimathea.
Of these fourteen stations, the first, the second, the fifth, the eighth, the tenth, the eleventh, the twelfth, the thirteenth, and the fourteenth have some explicit mention in Scripture.
One common way of observing Good Friday is to hold a Service of Shadows. As the service proceeds, the lights are gradually extinguished. The service ends in darkness. The disciples are scattered.
Holy Saturday
The dolorous week comes to a peaceful Sabbath rest; but it is the rest of suffering, and the peace of a tomb. Traditionally there is no communion, only the pause of eternity. There is an old tradition, only sporadically followed today, in which no food is taken at all for the forty hours prior to Sunday's sunrise.
Holy Saturday is the liturgical embodiment of the affirmation that Christ descended into hell, i.e., hades, sheol.
After sundown Easter Vigil begins. The world watches and waits as promise begins to unfold.
Easter Sunday
He is risen. Easter Vigil, in an old tradition still popular today, opens up into a sunrise service and meal, at which the great fast, both of the Triduum and of Lent, is broken. Easter shows the taking of the greatest evil -- the Crucifixion of God's Anointed -- and the turning of it into the greatest good -- new life for all who answer the call. To indicate this some churches have begun to display a Flowering Cross: a cross, symbol of torment and death, is put up on Good Friday that, on Easter Sunday, is decorated to overflowing with flowers.
There is also an old tradition in which there is a special baptismal service at the end of the Easter service. For as the Feast of Feasts, Easter is the day, beyond any other day, of new beginning, new hope, new life.