It is the second sacrament of Christian initiation. During the sacrament, we receive the Holy Spirit - with all the Spirits gifts and fruits - so as to become strong Christians and courageous witnesses of the faith.
The Bishop is the minister of the sacrament of confirmation, and during the ceremony he lays his hand on each of the candidates and anoints them with Chrism oil, saying: (mentions Confirmation name of the candidate) 'be sealed with the gift of the Holy Spirit.'
In this sacrament the Bishop prays for a special outpouring of the Holy Spirit on the recipients so that they can become mature and spirit-filled courageous Christians.
It depends on what one means by 'Biblical'. Everything we do as Catholics have their source and origin in Christ, and these we can find in the New Testament - especially the Gospels. The sacraments were instituted by Christ and that is why they are so life-changing for those who wish to co-operate with the graces inherent in them.
Jesus spoke a lot about the Holy Spirit that is coming to give strength to his disciples. And of course on the day of Pentecost, the spirit descended and those weak apostles and disciples and renewed their strength. The disciples, thus emboldened, were used by the Lord to impart his gift of the Holy Spirit on other people. Acts 8:14-17; Acts 9:17, and other passages in the New Testament speak of the laying on of hands so that people could receive the Holy Spirit.
Every year, the sacrament is organised in one of parishes in our cluster group. This pertains especially to it's reception by our primary school students in St Joseph's. Those primary school students not in Catholic schools, once they have approached the priests, are also able to receive the sacraments when they are appropriately prepared. (Preparation takes a couple of months - depending on their level of Catechism.)
On other occasions, catechumens for the Rite of Christian Initiation of Adults (RCIA) are prepared for the Easter Vigil. On that night, they receive the 3 sacraments of Initiation - Baptism, Confirmation and Holy Communion (with a 4th Sacrament - Sacrament of Penance or Confession) happening about a week after the Easter vigil.
Anytime really. You could meet any of the priests after morning mass - which is normally 10 am in St Columba's, or after the weekend masses: 4:30pm on Saturday, 11am and 5pm on Sunday. You will have to fill a little Sacramental Form and then continue from there.