In Gordon D. Fee (New Testament Exegesis: A Handbook for Students and Pastors [Philadelphia, PA: The Westminster Press, 1983], 32) identifies two criteria for what constitutes being worthy of a word study:
See the sources mentioned under "For Those Who Don't Know Hebrew or Greek," as well as the following:
Guide: For a guide to New Testament (Greek) word studies, see Gordon Fee's New Testament Exegesis: A Handbook for Students and Pastors (Philadelphia, PA: The Westminster Press, 1983), pp. 83-93. Much in this guide will prove helpful for Old Testament word studies as well.
There are a number of free language resources that can be helpful as you work on biblical translation. While they can't replace the reference works mentioned above, they can be a helpful supplement.
STEP Bible allows you to search scripture passages from multiple versions and translations.
Scholar's Gateway allows you to search scripture passages or words using public domain editions of the biblical text, and parses words.
TheBible.org allows you to search scripture passages and displays parallel versions.
Bible Hub allows you to search by keyword or passage from multiple versions and translations of the Bible.
Quizlet allows you to search sets of vocabulary flashcards uploaded by students. You can search by topic, professor, or class code.
Bill Mounce, author of Basics of Biblical Greek and other textbooks, has a number of instructional resources on his website.