Thanks for your question,
The following overview of Nehemiah is taken from a very useful website which includes a commentary on every book of the Bible.
Time: 445 – 432 BC.
Summary: The book begins with Nehemiah returning from Babylon as Governor of Jerusalem. He plans and oversees the rebuilding of the city wall despite discouraging opposition and disunity within the Jewish population. The wall is completed and more exiles are returned and registered as Jewish citizens. Nehemiah's dedication to God drives him to make several religious reforms including a public reading of the Law and arrangements for worship.
Time of writing: The mention of Darius the Persian (Neh 12:22) probably refers to Darius II, the successor of Artaxerxes I (Longimanus). Darius ruled from 423-404 BC. Therefore Nehemiah must have written the book sometime after that reign began. Since there are no references to Nehemiah's age in the text, it is hard to estimate how long he may have lived. When the book opens, he was second in command under King Artaxerxes. If he was 40 years old then and 41 when he reached Jerusalem in 444 BC, he would have been 62 years old in 423 BC when Darius replaced Artaxerxes. Consequently he probably wrote the book not long after 423 BC, most likely before 400 BC.
Nehemiah: "the wise master-builder" (1Co 3:10). Walls as spiritual strength and well-being: Pro 25:28; 16:32.
Nehemiah: a man of prayer: Neh 1:4-11; 2:4; 4:4,8,9; 5:19; 6:9,14; 13: 14,22,29,31.
The focus of restoration activities in Nehemiah is on the walls of Jerusalem. In Ezra it was the altar of burnt offerings and especially the temple in Jerusalem.
The walls of the city had lain in ruins since 586 BC. Then Nebuchadnezzar, king of Babylon, had breached them, entered Jerusalem, burned the temple, carried most of the remaining Jews off to Babylon, and knocked the walls down. Consequently the few Jews who remained could not defend themselves (2Ki 25:1-11). The returned exiles had attempted to rebuild the walls in or shortly after 458 BC, but that project failed because of local opposition (Ezra 4:12,23).
The returned exiles had received permission to return to their land and to reestablish their unique national institutions. Therefore they needed to rebuild the city walls to defend themselves against anyone who might want to interfere with and to interrupt their way of life.
Key verse: "So we rebuilt the wall till all of it reached half its height, for the people worked with all their heart" (Neh 4:6).
1. Nehemiah's arrival in Jerusalem: Neh 1:1 – 2:20
a) Tragic news from Jerusalem, and Nehemiah's prayer: Neh 1:1–11
b) The granting of Nehemiah's request: Neh 2:1–8
c) Nehemiah's survey of the walls, and his report: Neh 2:9–20
2. The building of the wall: Neh 3:1 – 7:4
a) The workmen and their tasks: Neh 3:1–32
b) The opposition of enemies: Neh 4:1–23
c) Reforms of Nehemiah as governor: Neh 5:1–19
d) The wall finished despite opposition: Neh 6:1–7:3
3. List of exiles: Neh 7:4–73a
4. Ezra's preaching and reforms: Neh 7:73b –- 10:39
a) The reading and observance of God's Law: Neh 7:73b – 8:18
b) A public confession and covenant: Neh 9:1–10:39
5. Lists of inhabitants of Judah and Jerusalem: Neh 11:1–12:26
a) New residents of Jerusalem: Neh 11:1–24
b) New residents of Judah: Neh 11:25–36
c) List of priests and Levites: Neh 12:1–26
6. Dedication of walls and organization of temple services: Neh 12:27–47
7. Nehemiah's second administration: Neh 13:1–31
a) Abuses during his absence: Neh 13:1–5
b) Nehemiah's return to Jerusalem: Neh 13:6–9
c) Reorganization and reforms: Neh 13:10–31
I hope you have found this helpful.