This page is my attempt to present a couple hundred words on each book to give you some bearings. I'm avoiding the dry, scholarly approach, and I'm not trying to pin down every fact, nuance, and theme. I'm giving you a starting point. I hope it helps. I welcome all comments, email me at andreww@farallon.com.
First of all, the date and author are unclear. Somewhere between Moses and Solomon, probably. It is clearly historical, the events really happened, but where the land of Uz lies, and whether Job was the king of Edom or just some semi-nomadic chieftan is unclear. We know he was a wealthy man well-known for his integrity, but that's it.
The Book Of Job concerns a fundamental topic, God's will and human suffering, which is probably never settled in any one person's mind, much less in literature. It is certainly subtler than other ancient literature in that each of the characters involved in the debate, including Job, say some things that are correct, and some that are wrong. Job's friends are clearly sympathetic to him, since they spent seven days and nights morning with him, but their "advice" is self-righteous and they assume Job is guilty.
Luckily, after all the arguments about fate and judgement have been layed out, God shows up and speaks out of a storm to settle *some* of them...
  | Matthew | Mark | Luke | John |
---|---|---|---|---|
Audience | Jews | Romans | Greeks | Church facing Gnosticism |
Title for Jesus | Son of David |   | Son of Man | Son of God |
Theme | The Messaiah-ship of Jesus and Coming of the Kingdom | The Power Of Jesus | The Humanity of Jesus | The Diety of Jesus |
  |   |   |   |   |
  |   |   |   |   |
The Gospel of Matthew features several sermons of Jesus, and thus contains a lot of his teachings. This gospel appears to be generally chronological, though there is some grouping of material by subject. This gospel is also the most quoted by early Christian writers.
Matthew, also known as Levi, was the tax collector who literally walked away from his booth when Jesus called him to follow, so he was an eyewitness to the events he records. Tax collectors were hated by the Jews as collaborators with the occupying Romans, and because most of them used their positions to extort a little extra income. Since Jesus' twelve apostles included a couple of radical anti-Roman activists, there must have been some interesting unrecorded moments.
The humanity of Jesus is stressed in the title "son of man," and Luke's genealogy of Jesus traces back to Adam. Luke also highlights Jesus's ministry to the poor and needy, and the role of women both in Jesus' life and in his parables.
His gospel is unique in claiming to be sequential. Luke spends more time than the other gospels on the incidents prior to Jesus's ministry: the angels' visits, John's and Jesus' births, and the childhood years. This portion of the book also includes four poetic passages, from Mary, Zechariah, the angels, and Simeon.
There is a strong theme of joy throughout Luke, from the birth announcements, the miracles and excitement surrounding Jesus, and the resurrection. Luke probably wrote this gospel between 60 and 64 AD, though possibly as late as 85AD. Luke was a physician and friend of Paul who also wrote the book of Acts, and traveled with Paul on a couple of occasions.
An Epistle is sent as a letter, but is intended for public reading. In the absence of any documents laying out Christian beliefs, the Epistle-writers gave their recipients some clear principles to hold to. This was very important in situations where congregations or groups began to believe and teach something untrue, which is explicitly mentioned in several books, including Corinthians and Galatians.
I suspect that letters to individuals such as Timothy and Titus were more than just instructions. Surely Paul must have given the instructions we see in 1 Timothy and Titus to these men verbally before leaving them. I believe these letters were written so that Timothy and Titus could carry our Paul's instruction with his authority. In these letters Paul tells them how to organize the church and who to put in charge, and explicit written instructions to this effect from Paul would have helped prevent opposition to these men.
These letters vary quite a bit. Some of the Epistles are very personal, and written out of nothing but love and longing, such as Thessalonians. Philemon seems to be person-to-person letter of the kind we're used to. Hebrews contains no explicit information on its writer or recipient, but appears to be a general missive to Hebrew converts, establishing Christianity as the culmination of Judaism.
You should be wondering how mail was sent in Roman times. While the Persians had an organized postal service as early as the sixth century BC, it was only for government use (ie taxation). By the Hellenistic time of Alexander the Great (circa 300BC) and on through New Testament times, many letters have been found, indicating that literacy and letter-writing were fairly widespread. While the rich would send a letter by slave or courier, ordinary citizens passed letters through caravans, friends, or passing strangers.