The season of Lent is a time especially devoted to the three-fold works enjoined upon us by our Lord, namely: fasting, prayer and almsgiving (see Matthew 6:1-18). As we heard in the Epistle on the last Sunday before Lent (1 Corinthians 13), none such things have any value in God's sight apart from charity, thus we must give heed not only to the outward works of faithfulness, but also to the inner life of love for God and neighbor from which they are meant to spring.
Thus the inner life is a subject for contemplation and examination during Lent. As we (God willing) cut out extra things from our daily schedules (be it TV or frivolous reading or video games or some other unnecessary diversion with which we sometimes fill our days) - we should "fill" that space with something intended to be spiritually profitable - the discipline of quiet before God, saying the Daily Office and/or Family Prayers, reading Scripture or attending a weekday service for which we do not usually make time (like the Stations of the Cross, etc.).
All Christians whose health or age does not exempt them should submit to the Lenten fast. Traditionally, each day in Lent is a day of abstinence, typically from meat and dairy. Additionally, each Wednesday and Friday of the week (most especially Ash Wednesday and Good Friday) are strict fasts. (Sundays, on the other hand, are never fast days - they are weekly feasts of Christ's resurrection.)
Fasting from food makes us hungry. Our bodies need to eat and our flesh protests when it doesn't gets the food to which we are accustomed.
It is profitable for us to feel hungry, though many of us avoid this at almost any cost. We thoughtlessly assume that hunger is an evil to be avoided, chased away with snacks and sodas and distractions. And so at meal time we over-eat, indulging ourselves and our every want. What little self denial we exert is often times to some superficial or self-centered end: we want to be thinner than we are, or to be more "fashionable" or we do not order dessert so that he or she (whomever that may be) does not see us eating it. Though it is good to show restraint at the table for the sake of health (in fact this is an aspect of being a good steward of the life that God has given to us), fasting is not a remedy to improve your health or social acceptability. Fasting is for the good of your soul. We need to learn to say "no" to ourselves - to our cravings and affections and desires. Fasting is a means to that end. In fasting we subject ourselves to training - we deny ourselves something that we want to eat (or that we would normally eat) for the sake of the strengthening of our wills. Learning to say "no" at the table is preparation for saying "no" to other (presumably more dangerous) temptations.
As already mentioned, the disciplines of Lent are threefold, thus there is more involved in the keeping of a holy Lent than fasting. By skipping a meal, we have "extra" time - time that we might not have had otherwise. Plan to use this time in a spiritually profitable manner. Spend some time in prayer (even if it is only 10 minutes). Or simply be quiet before God, seeking to resist the manifold distractions that will inevitably assail you. Read the Scriptures more than you might otherwise. Look up the texts appointed for the day and read them slowly - perhaps even more than once. Think about their meaning and write down thoughts that occur to you. Memorize a verse or a passage and later recall and meditate upon it.
Fasting and Prayer - those are the first 2 disciplines of Lent. The 3rd is almsgiving. It is to be expected that you will spend less money on yourself during Lent than at other times of the year. Lent is not a time for self-indulgence or parties. Additionally, you will be eating less often and less extravagantly. Meat is expensive and to cut it out will put a bit of extra cash in your pocket. Instead of spending this on yourself or on something frivolous, why not give this to God as well? Normally you would have spent this money to feed yourself, but now these funds are available for you to give away for someone else's benefit. Give them (secretly, if possible) to someone in need. If you really cannot think of anyone to whom to give your alms, give them to your church or to your priest to be used in some good work. This is the third discipline of Lent - almsgiving.
Seek the Lord during these 40 days. Seek to die to yourself and grow in love for God and neighbor. Find time to keep silent vigil before the Lord. Pray. Fast. Give alms. Attend the services which the Church offers for your spiritual health and prepare yourself in advance for them. May this Lenten season be a time of great spiritual growth for us, as we pray for the gift of repentance and seek to humble ourselves before the Lord in order that, in His good time He may lift us up to Himself. Let us pray that God would give us His grace such that we might keep a holy Lent, to His glory and to the good of our souls.