"The Season of Lent is an annual period of forty days beginning on Ash Wednesday...., which is set aside for penance, fasting, and almsgiving in preparation for the coming celebration of Easter. It is modeled in part on the forty days that Jesus spent in the desert prior to beginning his public ministry. The penance, fasting, and almsgiving are meant to help lead the believer to ongoing conversion and a deeper faith in the Lord who redeemed us." (US Catholic Catechism for Adults)
"The seasons and days of penance in the course of the liturgical year (Lent, and each Friday in memory of the death of the Lord) are intense moments of the Church's penitential practice. These times are particularly appropriate for spiritual exercises, penitential liturgies, pilgrimages as signs of penance, voluntary self-denial such as fasting and almsgiving, and fraternal sharing (charitable and missionary works)." (Catechism of the Catholic Church,1438)
Helpful links for Lent: