The ancient Greek translation of the Old Testament is important. Since it's likely to come up in class and will definitely come up in your study, I want to make sure you know a few things about it, and point you to where you can find an English version.
It's called the Septuagint (sep-TOO-uh-jint), from the Greek word for "seventy," and is therefore also identified by the Roman numeral for 70: LXX. The number 70 is an old Hebrew stereotype meaning the whole world, or sometimes the world outside Israel (the idea being that there are seventy nations). You can see this idea in both the Old Testament and the New. The LXX is the earliest known translation of the Old Testament into another language -- some parts of it are pre-Jesus, even as early as 200 B.C.
The really interesting thing about this old Greek translation is that it's often very different from the Hebrew, in two ways: First, it contains books or parts of books that aren't preserved in Hebrew, but were considered by the ancient Jewish translators part of scripture (for instance, the Wisdom of Jesus Ben Sirach or the extra chapters of Daniel and Jeremiah).
Second, the LXX contains some very different readings from the traditional Hebrew text of the Bible (the Masoretic text, or MT). For instance, Deuteronomy 32:8 in the MT says that God divided the world up according to the sons of Israel, but in the LXX the same verse says that God divided the world according to the sons of God... these are radically different ideas.
To really come to grips with the differences between the LXX and the MT and why they matter, you'll need some Greek and Hebrew (there's my little pitch, again). But for starters, you can find the New English Translation of the Septuagint in its entirety online, here (I know, the web-page looks a little hokey, but the LXX translation itself is good, and downloadable in .pdf). You can also buy a physical copy of the book.