Complex sentence: Practically nothing is known about Habakkuk's personal history, except for what can be inferred from the text of his book, which consists of five oracles about the Chaldeans (Babylonians) and a song of praise to God.
Split into simpler sentences: Practically nothing is known about Habakkuk's personal history, except for what can be inferred from the text of his book. The book of Habbakuk consists of five oracles about the Chaldeans (Babylonians) and a song of praise to God.