crescent, if I were you, I would avoid that Ramadan thread like the plague - it's much easier to turn the other cheek when you don't know what's being said. There is a line in the book of Amos in the OT that say Therefore the prudent keep quiet in such times, for the times are evil. I think that is an appropriate verse for a lot of what is said on here.
The Book of James is an odd one in the NT. It's written as a letter, but not to anyone in particular. It's a bit like the Book of Hebrews, in some ways, as we don't really know who wrote it. Both books are a sort of NT wisdom literature, like the books of Proverbs and Ecclesiastes in the OT.
We kind of think that James was written by James the brother of Jesus, there is some evidence for this in other NT books etc. The theory is that the Book of James is a sort of collection of his teachings made up into a form of letter for distribution to the early churches. So the voice is James the brother of Jesus, but under the influence of the Holy Spirit, guiding him in what to say and write.
This is kind of how we believe the bible was written. 1st Timothy 3:16 says that All scripture is inspired of God some translations say "God-breathed". So, just like the angel told Muhammed what to write or communicate, so the Holy Spirit (the aspect of God that does stuff) led the bible writers. We also believe that the Holy Spirit guided the early Christians and the apostles in their preaching, teaching and faith - that's why the apostles could heal, speak in tongues and the like.
As far as structure goes, the NT has 2 distinct sections.
There are the 4 Gospels and the Book of Acts of the Apostles, which are basically the stories of Jesus when He was here on earth. These are where we find the recorded words of Jesus, the stories of his birth, death and resurrection and stuff like that. The Book of Acts records the acts of the apostles in the aftermath of Jesus's death and the very early growth of the church.
After that there are the various Letters and the Revelation of St. John the Divine. The letters are documents written by the Apostles to the early churches throughout the Roman Empire. It is in these letters that we see the development of Christian belief and theology. A lot of them are written by the apostle Paul, but there are also letters written by Peter, John, James, the brother of Jesus and Jude, the brother of Jesus. The epistles talk a lot about remaining constant in the faith and about how we should live. The contain guidance on marriage, parenting, community responsibility and all sort s of things.
The Revelation is what we call Apocalyptic literature. It deals with John's vision of the End Times and the Day of the Lord, which early Christians expected at any second. Modern Christians kind of expect the Day of the Lord and Christ's 2nd Coming, we work towards it and hope for it, but we don't think that we know when it will happen. we believe that only God knows that.
The OT is divided up into 3 sections - historical, poetical and prophetic.
The historical section starts with Genesis and ends with Esther. It records the history of the world as the Hebrews saw it. it also records the history of God's relationship with his people. The first 5 books (pentateuch) are attributed to Moses and contain all the Laws that governed the lives of the early Israelites. The authorship of the other historical books is traditionally attributed to various prophets of God, but there is a huge amount of scholarship and controversy around this issue, between the bible literalists and more progressive folk. For instance, I know a chap who absolutely believes that the Adam and Eve story happened exactly as it is written in Genesis and that the book of Job is a true story, written by a man named Job about his experiences. Most folk believe that Job is a piece of Wisdom writing and an allegory about the fact that bad things happening to good people and about doubt.
The poetic books are the bible's Wisdom writings. They run from Job through to Song of Songs. They are all about faith and the way to live life and are, generally, attributed to people like David and Solomon.
The there are the 18 prophetic books, divided into 6 major and 12 Minor prophets. These books are named after the people who claim to have written them, in the main. The Minor prophets mostly begin by saying things like - This is the Vision of... sent to him by God..., so that's where they get their names. There is a lot of dispute over the authorship of the major prophets, but again, traditionalist believe that they are named after the person who wrote them.