My second recommendation in this vein is simply to get ahold of some good textbooks on Biblical Greek in order to gain a basic understanding of this ancient language. The ones I have, which I understand are among the most commonly used texts for first and second Greek courses in seminaries, are Basics of Biblical Greek Grammar, by William D. Mounce, and Greek Grammar Beyond the Basics, by Daniel B. Wallace.
There is a saying that goes, "A little knowledge is a dangerous thing." In other words, a slight understanding of a topic can be more harmful than no knowledge at all. A person with a little knowledge of a subject may be tempted to see himself as an authority on the subject, and may misapply his little knowledge and draw invalid conclusions. Such is the case with Biblical languages. Many a student has appealed assertively to the original Greek in support of a particular interpretation of a Bible passage, while in fact his study of the Greek text was limited to looking up one or two key words in a lexicon or concordance. New Testament scholar D.A. Carson has coined the phrase "Word Study Fallacy" to capture how this Bible study shortcut can hinder one's ability to discern true meaning. Word studies can be helpful, but one can study the Greek word theos for hours upon end and will still not have the key to understanding Thomas' exclamation in John 20:28.
In order to become a doctor, you must not only understand the individual parts and organs of the human body, but the systems; how it all works together. In the same way, there is far more to language than individual words. To be able to use a language accurately, one must understand the systems by which words work together to form meaning; namely, grammar.
In this blog I have emphasized the usefulness of learning Biblical Greek to further your Bible study skills. It is of course also very useful to learn Biblical Hebrew. I would consider Greek to be a higher priority for the following reason: it gives the student access to ancient texts of both Testaments. The Septuagint (Greek Old Testament), while a translation of the original Hebrew, was used widely by first century Jews and Christians, including New Testament writers, suggesting it is accurate and trustworthy. It was written only about three centuries before the New Testament, so the language is not too different.