The rosary is one of the most powerful weapons we have against satan, and Our Lady promises many graces to those who pray it. Praying the rosary is not repetitiously repeating prayers over and over again.
There are now twenty "mysteries" of the rosary, which we meditate upon while reciting the prayers of the rosary. Eighteen of these mysteries are taken directly from the bible and constitute three periods of Jesus life (birth, ministry, death, and resurrection). The last two mysteries are dogmatic and are truths of our Catholic faith. There is no greater way to gain knowledge and be drawn into a deeper understanding of Jesus' life than praying the rosary, since it is scriptural. I can't say enough about the incredible graces that come as a result of praying the rosary. Our Lady asks that we pray all 20 decades every day, and asks that every family pray 5 decades of the rosary as a family together as well as reading a small passage of the bible every day.