The Dead Sea Scrolls can be divided into two categories—biblical and non-biblical. Fragments of every book of the Old Testament (Hebrew canon) have been discovered, except for the book of Esther. Now identified among the scrolls are 19 fragments of Isaiah, 25 fragments of Deuteronomy and 30 fragments of the Psalms. The virtually intact Isaiah Scroll, which contains some of the most dramatic Messianic prophecy, is 1,000 years older than any previously known copy of Isaiah.
In addition to the biblical manuscripts, there are commentaries on the Hebrew canon, paraphrases that expand on the Torah, community standards and regulations, rules of war, non-canonical psalms, hymnals and sermons. Most of the texts are written in Hebrew and Aramaic, with a few in Greek.
The Dead Sea Scrolls appear to be the library of a Jewish sect, considered most likely the Essenes.They comprise the oldest group of Old Testament manuscripts ever found, dating back to 100–200 B.C. This is dramatic, because we now have absolute evidence that Messianic prophecies contained in today’s Old Testament (both Jewish and Christian) are the same Messianic prophecies that existed prior to the time Jesus walked on this earth.
http://www.allaboutarchaeology.org/dead-sea-scrolls.htm
The Dead Sea Scrolls have provided phenomenal evidence for the credibility of biblical scripture. Specifically, the nearly intact Great Isaiah Scroll is almost identical to the most recent manuscript version of the Masoretic text from the 900’s AD. (Scholars have discovered a handful of spelling and tense-oriented scribal errors, but nothing of significance.) In light of Isaiah’s rich Messianic prophecy, we thought it would be rewarding to reproduce a portion of the English translation of the actual Hebrew text found in the Great Isaiah Scroll.
http://www.allaboutarchaeology.org/dead-sea-scrolls-2.htm