Orthodoxy 101
Father Thomas Hopko's "Rainbow Series" is a great starting place to begin learning about orthodoxy. Click the books to find them on Amazon, or you can click here to get free online access to them at the Orthodox Church in America website. Additionally, recently Hieromonk Gregorios published his Orthodox Faith, Worship, and Life which is quickly becoming recognized as another "must read" Orthodox 101 book.
For those who prefer podcasts, Fr. Hopko's podcast on Ancient Faith Radio is very helpful as well.
Orthodox Spirituality
Metropolitan Anthony Bloom's classic Beginning to Pray is an excellent place to start for growing in a life of prayer. In fact, it's a great reference point for the whole life of prayer. Along with Met. Anthony, Metropolitan Kallistos Ware's classic The Orthodox Way in which he emphasizes the union of dogma, liturgy, and prayer as the way of Orthodoxy is another wonderful title to read. The lives and spiritual teachings of the saints provide light to our path as Orthodox. Elder Thaddeus' Our Thoughts Determine our Lives and St. Porphyrios' Wounded by Love are touchstones of the Orthodox spiritual life as lived by these two holy men of recent memory.
Orthodox Liturgical Life
The central focus of the Christian life is Christ, and there is nothing on earth that rivals our experience of Him in the reading of His Holy Gospel and receiving His divine life into us at Holy Communion. Therefore, it is in the Divine Liturgy, and the services that accompany it, that Orthodoxy is most fully expressed and experienced. Hieromonk Gregorios' The Divine Liturgy: A Commentary in light of the Fathers is an excellent place to start. St. Germanus' On the Divine Liturgy, written in the 700's, remains an easily accessible explanation of the Divine Liturgy.