Habakkuk 1 - Habakkuk wrestles with God concerning the topic of evil. God shows Himself to be righteous - He will judge rightly.
Habakkuk 2 - God shows Habakkuk the heart of wickedness and the heart of righteousness.
The wicked are "proud" (Hab 2:4-5). They are controlled by their lusts. The wicked person "enlarges his desire as hell" and "cannot be satisfied" (Hab 2:5). What he does, he does "for himself" (Hab 2:5). The wicked person desires "that he may be delivered from the power of disaster" but to accomplish this, he "covets evil gain" and "sins" by cutting off many peoples (Hab 2:9-10). The wicked commit violence and shame others in an attempt to glorify themselves (Hab 2:15-17). In the end, the Lord says that the wicked are idolaters. They do not worship the true God.
The righteous are people of "faith" (Hab 2:4) who stand in silence before the true God (Hab 2:20). They listen to God - in the sense that they hear and obey Him (Hab 2:2-3).
Looking at the chapter this way, I feel like I'm reading Romans 1-3!
Habakkuk 3 - Habakkuk praises God with trembling, confidence, and joy.
This book teaches us to:
1. wrestle with God in prayer (Hab 1-3)
2. wait for God (Hab 2:1, 2:3)
3. listen to God (Hab 2:1-2)
4. trust God (Hab 2:4, 3:19)
5. repent of evil (Hab 2:5-19)
6. keep silence before God (Hab 2:20)
7. praise God (Hab 3)
8. tremble before God's word (Hab 3:2, 3:16)
9. remember what God has done (Hab 3:3-15)
10. rejoice in God (Hab 3:18)
You can read Habakkuk in the Bible. This little book is located toward the end of the Old Testament.