Where did the rosary come from? What are the "mysteries" and when are they supposed to be done?
--Musing in Manchester
The rosary began as a way for people to pray the psalms and the Liturgy of the Hours (Morning, Evening and Night Prayers which use the psalms). Since most lay families were unable to read or commit the psalms to memory, they learned [or were taught] the "Hail Mary," an easy prayer to say and recite. As there are 150 psalms, so there were 150 beads which were woven together. Some rosaries were not as big, but the general idea was that decades of "Hail Mary's" would be said in praise to God through this mantra. Certain mysteries of the rosary, reflecting on the mysteries or moments of Christ's and Mary's life, were added to give a scriptural and traditional reflection for the person and their own way of entering into the mysteries of their life with God.
So on Sundays, Wednesdays and Saturdays, the "glorious mysteries" are recited first [that is, for each decade. Some who do all 150 "Hail Marys" and reflect on all of the mysteries each day]. The "glorious mysteries" are the Resurrection, the Ascension of our Lord, Pentecost [or the decent of the Holy Spirit], the Assumption of Mary, and the Queenship of Mary.
On Mondays, we are called to reflect on the "joyful mysteries:" the Annunciation of our lord, the Visitation of Elizabeth, the Nativity of our Lord, the Presentation of Our Lord and the Finding of Our Lord in the temple.
On Tuesdays and Fridays, the "sorrowful mysteries" are reflected upon: the Agony in the Garden, the Trial before Pilate, the Carrying of the Cross, the Stripping of Garments, the Crucifixion.
On Thursdays the "luminous" mysteries are reflected upon.
The order of prayers around the beads is this:
1.on the cross/crucifix: the Apostles Creed is said
2. first bead: Lord's Prayer
3. three beads: Hail Marys: meditating on the gifts of faith, hope and charity/love
4. then a "Glory to the Father"
Then one can go in either direction around the circle of the rosary. On the first bead, one the of mysteries is announced and reflected upon, such as the Resurrection, the Annunciation or the Agony in the Garden: Lord's Prayer, 10 beads of "Hail Marys and then a "Glory to the Father."
At the end of the 5 decades, one may continue and do another round of mysteries or end with the "Hail Holy Queen" prayer. Sometimes people will say additional prayers in between each decade [10 hail Marys]. These are optional and were added in this century by different Catholic religious groups for devotional purposes.