They’ve produced satellite maps and KMLs (for Google Earth) for every book in the Bible that mentions a place, and KMLs for every chapter. Even better, all the data and maps are available under a Creative Commons license.
Jonah provides one of the best examples of how maps can help you study the Bible:
Jonah starts out near Joppa. God tells him to go to Nineveh, so what does Jonah do? He heads to Tarshish, about as far away from Nineveh as he can get. Knowing this geography reinforces the comic aspects (in a literary sense) of Jonah’s character.
They also have an intriguing blog post (with pictures!) that highlights the changing geography over time in the Bible.
Full disclosure: a Crossway staff member helped develop the site.