Multi-volume encyclopedias are good sources for historical and biblical themes. But background information does not impose meaning.
Lexicons & dictionaries can reveal what might be “lost in translation” but they also tempt us to fall into the trap of “I learned a fact about a word and I must use it.”
A concordance is an organized list of all the biblical texts which contain a given word. Concordances allow you to broaden your understanding of how a word is used and its range of meanings.
You’ll be surprised at how the information on a map can open your study. Consider how knowing that the road to Jericho was 17-miles changes the parable of the good Samaritan.
Since every translation is an interpretation of the original language, you should consult several translations of different types when studying the Bible. Bibles fall on an interpretation scale and it will improve your study if you know the difference and have one of each type.