Finally, the translators state the purpose and plan of the present translation. They have not intended to make a new translation, but to make the best possible translation by improving upon previous ones. To do so they have, of course, carefully examined the original Hebrew and Greek since translation should only be done from the original tongues. Also, they did not work hastily, as did the translators of the Septuagint, who, according to legend, finished their work in only seventy-two days. The translators also availed themselves of commentaries and translations of the Scriptures in other languages. In their work they felt it was essential to include marginal notes, despite the fact that some might feel such notes tend to undermine the authority of the Scriptures. These notes are essential since the translators confess that oftentimes they were unsure how a word or phrase should be translated. This is especially true in Hebrew, where there are a number of words which only occur once in Scripture, and even the Jews themselves are uncertain about their translation. And so, as Augustine notes, a “variety of translations is profitable for finding out of the sense of the Scriptures.” Lastly, the translators observe that, in spite of criticism from some quarters, they decided not to always translate the same Hebrew or Greek word with the same English word and have retained, over the objections of the Puritans, the old ecclesiastical words like “baptism” instead of “washings.”
http://dbts.edu/blog/the-embarrassing-preface-to-the-king-james-version/
Did I give the impression that I'm a King James-only advocate?