You will find an introduction and outline to Zephaniah here.
Here is a from the Book of Common Worship to use before reading.
Blessed Lord, who caused all holy scriptures to be written for our learning: Grant us so to hear them, read, mark, learn, and inwardly digest them, that we may embrace and ever hold fast the blessed hope of everlasting life, which you have given us in our Saviour Jesus Christ. Amen.
An Outline of Zephaniah (After O’Dell)
I. Superscription 1:1: This verse tells us much about the book. It begins with the prophetic introduction “The word of the Lord”. All we know about Zephaniah is found in this verse. His name means “Yahweh has hidden/protected/treasured”. The genealogy tells us interesting things. “Cushi” , in other places, means Ethiopian or Cushite. It may be a name or may refer to ethnicity. Hezekiah is an uncommon name and may refer to the Judean king (2 Kings 18). What do these two things tell us about Zephaniah? Lastly the superscription tells us the date and context of Zephaniah and his oracles.
II. 1:2-2:3 Judgment on Jerusalem
1. Reversal of Creation 1:2-6:Notice how the language in the first verses echo the first chapters of Genesis and the flood story. Then in verses 4-6 the focus turns to Judah. The host of heavens refers to Assyrian astral gods. Milcom is an Ammonite god. Ball is a Canaanite god. Syncretism, the combination of worship of the God with other gods is the cause of this coming destruction
2. The Day of Yahweh 1:7-18: The Day of the Lord is a time of punishment and destruction. The “day” is more likely an era of time. The language used to describe the events is the language of theophany rather then a description of particular events. However it was a way of claiming that God was active in historical events, such as, the decline of the Assyrian Empire and the changes that brought. These verses begin with punishment of the court officials and royal family. In verse 9 “leap over a threshold” refers to a pagan religious practice. Then the focus shifts to merchants and traders and the religiously indifferent.In verse 12 “rest complacently on their dregs” is a reference to wine making. If wine is not properly prepared it becomes thick and sour.
3. Call to Repentance 2:1-3: The destruction of the Day of the Lord is not inevitable. The humble who seek the Lord will be spared.
III. 2:4-15 Oracles Against the Nations
1. Philistia 1:4-7: Four Philistine cites are named. Notice the imagery of sheep and shepherd.
2. Moab and Ammon 2:8-10:These are traditional enemies of Israel located to the east of Israel.
3. Assyria and the Gods of the Nations 2:11-15: Notice in verse 11 God is victorious over all the other gods. People believed that the strength of a god was reflected in the strength of a nation and visa versa. Nineveh was the capital of Assyria. It was common in the ancient world that threats against cities or nations described them becoming empty except for wild animals living where humans lived before.
IV 3:1-20 Jerusalem’s Response: Now the focus returns to Jerusalem and the book ends with a word of hope.
1. Yahweh’s Decision 3:1-13: The city is Jerusalem. Notice that all the ruling elite are mentioned, officials, judges, prophets and priests. Notice the animal imagery. What was Jerusalem accused of. In verses 6-7, what happened to the other nations should serve as a warning to Jerusalem. Verse 8-13, all the nations will be converted and turn to God. A remnant of Israel will also return to God.
2. Yahweh is King 3:14-20: The joy of restoration. Verses 14-15 are like a psalm of enthronement. (compare Psalm 47,97) The references of bringing people home probably reflects a post exile addition to the book.
Read More About It:
Here are several good sources to aid your reading.
Anderson, Bernhard W., Katheryn Pfister Darr, Understanding the Old Testament Abridged fourth Edition. (Upper Saddle River,New Jersey: Prentice Hall) 1998.
The New Interpreter’s Bible, Vol 7, Keck, Leander E. ed. (Nashville: Abingdon Press) 2001.
Hicks, R. Lansing, Walter Brueggemann, “Zephaniah” in The New Oxford Annotated Bible with Apocryphal/Deuterocanonical Books, Metzger,Bruce M.;Murphy,Roland E., eds. (New York:Oxford University Press) 1994.
O’Dell, Margaret S. “Zephaniah” in HarperCollins Bible Commentary Mays, James L. ed.(San Francisco: HarperSanFrancisco) 2000.
O’Brien, Julia M. “Zpehaniah” in The New Oxford Annotated Bible with Apocrypha: New Revised Standard Version.Coogan, Michael D.; Brettler, Marc Z.; Perkins, Pheme; Newsom, Carol A. (2010-01-20) Oxford University Press. Kindle Edition.