Along with our UM Hymnal, the UM Book of worship is the definitive worship and prayer book of The United Methodist Church. It contains all of the classic liturgies of the hymnal (for the administration of the sacraments, marriage, funeral, morning and evening prayer, etc.) plus much more. Indeed the preface notes that our worship books define our church. This will be all the more true as our churches move towards a liturgical practice that conforms to our official worship books as called for in "This Holy Mystery," a statement adopted by the General Conference of 2004, calling on our pastors and bishops to "be loyal to the liturgy of the church" in the way they plan and conduct worship.
Looking back to the "Sunday Service" book, which John Wesley prepared for the early Methodists by revising the Book of Common Prayer of the Church of England, the preface notes that this too is a worship book with an Anglican hertiage, and many of the prayers and services are clearly influenced by or very often taken directly from The Book of Common Prayer.
This Book includes Holy Communion in both forms: the modern and traditional language, with the seasonal conmunion prayers throughout the Christian year. It includes the services and liturgies for Holy Baptism, Christian Marriage, Christian Burial. It includes prayers to be said with the dying and with the surviving family immediately after a death (i.e. "Last Rites"). It has numerous resources - prayers, greetings, hymn suggestions and so on, for Sundays and Holy-days throughout the Christian year (including services for Ash Wednesday and the various traditional services and devotions of Holy Week). It includes the 4 daily offices (Morning, Mid-day, Evening, and Night services of Praise and Prayer), and services for annointing with oil and healing (healing service #2 also lends itself to serving as a form for the confessional). It offers numerous prayers and blessings for many occassions (many composed by important figures from across Church history) and finally the various services for ordering the church (ordinations for bishops, elders, and deacons, commissioning of missionaries, consecrating of church buildings and sacred furniture, etc.). It also has orders for traditional Wesleyan servies such as the Love Feast or the watchnight service, plus the lectionary and instructions about observing the Christian year.
Basically, if you are a United Methodist pastor you should have this book and should be using it each week, as General Conference has declared. If you are a Methodist/Wesleyan lay person who wants to pray the daily office or learn to pray with and learn from the tradition of our church, this is a must-have resource.
My only complaint is that, while most of the prayers and blessings come from older Methodist books of worship or the Book of Common Prayer or similar classically-grounded sources, a few more "generic" prayers from non-Christian traditions have been included for (I suspect) purposes of political correctness, and I strongly suspect that these prayers will be seldom used in the life of our Church, and essentially amount to wasted space in an otherwise excellent prayer and worship book. On the whole, though, this book is a must-have for United Methodist leaders and also for other Wesleyan Christians interested in liturgical prayer.