If an entry in a general-purpose dictionary or encyclopedia is insufficient, consider turning to one of these more specialized resources, which are more narrow in scope. They will typically have more detailed information about topics, whether you are researching people or places in the Bible (e.g., Goliath or Canaan), a specific idea or theme (e.g., Kingdom of God in the Gospels), or even the individual books of the Bible.
Many entries in these resources have bibliographies which can assist you in deepening your research.