This is the book most people dread reading when they commit to go through the Scriptures. It starts off with descriptions of various offerings and then goes into priestly garments...not inspiring stuff. Unless you know some of the background.
The book of Leviticus is the book of the Levites. The priests were to come from the tribe of Levi, specifically from the family line of Aaron, Moses brother. The book of the Levites then prescribes all the details of their religious duties.
Why do we have this book in the Bible? Call it religious transparency. It is a detailed glimpse into the intracies of how an ancient people were to live out their religion. Religion was an all encompassing way of life, so the offerings are varied, covering different aspects of this complicated way of life.
The book of Leviticus and of Hebrews is intentionally paired together. In the book of Hebrews Jesus is presented as the Great Priest, greater then those of the Levites. In reading about the details of atonement, sin, sacrifices and blood in Leviticus, we get more background to why and what Jesus did in his life and ministry before, during and following the cross. Hebrews helps us better understand Jesus from a Levitical point of view.
It is not easy reading, but keep this in mind: Leviticus gives us background to the sacrificial and priestly part of Jesus. Even if you don't understand it all, keep the big picture in mind.
And don't worry, you'll be done with Leviticus in two weeks!