The language of the Bible
The Old Testament has mainly been written in Hebrew. A few parts of the books Ezra, Nehemiah and Daniel have been written in Aramaic. Hebrew was the classical language of old Israel, Aramaic was a later dialect, the language of the people, the everyday speech of the Jews in the East. The New Testament has been written in Greek, the world language of that age, with a few minor exceptions (some Aramaic and Latin words).

The manuscripts of the Bible
Today we are in possession of a few thousand old manuscripts. Most of them only contain just a part of the Bible or they are fragments with a few verses or chapters. They are hand written on sheets of papyrus. Joint together to something like a book they are called codex. Sometimes the texts are written on scrolls of parchment. The oldest fragments from the Old Testament are from the second century B.C. The oldest fragments from the New Testament are from the second century A.D. (a fragment from the gospel of John from around 125 is the oldest New Testament fragment).
The following manuscripts are the most extensive manuscripts.

The Qumran texts (Arabic: Chirbet Qumran, which means 'ruin of Qumran').
In 1947 Bedouin shepherds found several parchment scrolls which were wrapped in linen cloths and which were stored in jars of clay in a cave in Wadi Qumran (the valley of Qumran), at the north-west cost of the Dead Sea, 14 kilometres south from Jericho. They came from the Jewish sect of the Essenes. Most probable the Essene monks, threatened by Romans (66 and 132 A.D.), wanted to keep their valuable religious manuscripts save until calmer times. After this discovery a huge number of scrolls were found in eleven other caves; one scroll with the complete text of Isaiah, fragments from all Old Testament manuscripts except Esther, commentaries (often with the Old Testament text), apocrypha and writings of the Essene sect. Those manuscripts are probably from the second and first century B.C. and are therefore the oldest handwritings of the Bible that we have. They are of invaluable importance for the investigation of the original text and the investigation of the Jewish religion and early Christianity.

The Codex Sinaiticus
Until recently this manuscript was the oldest manuscript, it dates from the fourth century. It was discovered in 1859 by Constantin Tischenforf in the monastery of St.Catharina at the foot of Mount Sinai and transported to the imperial library in St.Petersborough.. This codex contains almost all of the Old Testament (the Greek translation) and the complete New Testament. In 1934 the English bought the manuscripts for at about 450 thousand euro. Since then it has been on display in the British Museum in London.

The Codex Alexandrinus
The manuscripts were written around the year 450 in Egypt and the patriarch of Constantinople stayed in possession of it for a long time. It contains the Old Testament and almost all of the New Testament from the 25th hapter of Matthew onwards. Right now it's in the British Museum. The British Museum inherited it from George II in 1753.

The Codex Vaticanus
It was written in Egypt around the middle of the fourth century. Now it's in the Vatican. This manuscript also contains the Greek Bible, but quite big parts of the New Testament are missing (the ending of the letter to the Hebrews, the Pastoral Letters and Revelation are missing). The excellent manuscript is difficult to read because the text was restored with new ink and because it was often changed.

The Codex Ephraemi Rescriptus
This manuscript was written in Egypt around the middle of the 5th century.
Right now it's in Paris. It carries the name of the church father Ephraim, because his text was written over it. The original manuscripts were restored by Tischendorf with the use of chemicals. It was published between 1843 and 1845. 

The Codex Cantabrigiensis and the Codex Claramontanus
Both manuscripts, written around 550 and with Latin translation, belong to Theodorus Beza in Geneva.