One particular way Catholics can pray for people in need is through having a Mass said for that intention.
The greatest and most powerful prayer we have is the Mass, since the fruits of the Mass are the very fruits of Jesus' redemption made present to us.
A Mass intention may be requested for: one who has died; one who is sick or suffering; one who is celebrating a birthday, anniversary or other special moment in their life; in thanksgiving to God; or for a prayer intention.