Authorship and Origin:

The man Malachi is essentially unknown from the Old Testament, except for his writings. Nothing is known of where he came from or his family. However based on the content of the book, he must have lived around 465 B.C. until 430 B.C..

Overview and Significant sections

Malachi speaks to a lukewarm group of believers who returned from Babylonian exile only about 70 years ago. The Jews has struggled to reestablish themselves and the temple in a hostile land. He ministers to a people who have lost excitement and have lost touch with their God. The people have drifted and wonder if God is there. Malachi has a message for us today, who sometimes feel the same driftings.

Significant sections:

For more detailed study:
Read it. (the entire book is available here.)
The Concise Matthew Henry Commentary on this book. study of this book.
the World Wide Study Bible has Dictionary, Commentary, Scripture and sermons available on this book.