I first discovered the Liturgy of the Hours while on retreat with Marianists. We read in scripture that we are to pray always. The Liturgy of the Hours is one way that is done by the universal Church as a whole, by recognizing each day that God gives us and the hours within that day. It is the prayer that is prayed within monasteries and religious communities, but it is not limited to the professed. The primary hours are Lauds (morning prayer) and Vespers (evening prayer) which are traditionally prayed at 6am and 6pm. There is also midmorning and afternoon prayer at 9am and 3pm as well as noon prayer and compline, or night prayer at 9pm. The Office consists of psalms, a short scriptural reading and intercessory prayers. Each prayer ends with the Our Father followed by a closing prayer. Within Lauds can be found the prayer Zechariah prayed at the birth of John. At Vespers, we have the Magnificat. Compline at the close of day has the prayer of Simeon at the Presentation and is followed by a Marian prayer like Salve Regina.
I generally pray Lauds and Vespers. I also pray the Office of Readings which is also included within the Divine Office without a specific time attached. With the Office of Readings, I read the scriptural readings listed at the back of my Christian Prayer plus a chapter or section from a devotional book. I just completed Dark Soul of the Night in this manner. I carry a Shorter Christian Prayer in my backpack for times when I may not be home for Vespers. The Christian Prayer that I carry is only one volume and has a 4 week cycle of prayers used for the Liturgy of the Hours. There is also a 4 volume edition.