My main Bible is a New Student Bible (NIV), which has a lot of explanatory notes in it. The introduction to Leviticus had an interesting analogy:
Leviticus reads something like a training manual for atomic plant workers. Its “dangerous material,” however, is more powerful than the atom. Leviticus gives exhaustive detail on how to live with God.
A pamphlet on “how to survive a nuclear accident” may be dull if read on vacation, but it’s gripping if read in a vibrating nuclear reactor. Similarly, Leviticus is dull if you do not realize the wonderful news behind it: a powerful God, the Creator of the universe, has entered the life of a small and insignificant tribe. The Israelites could not merely fit this God into their lives. They needed to restructure their lifes—food, sex, economics—to fit with his. It was essential not just for priests, but for everyone.
Ignoring this manual could be deadly. It was for Aaron’s two sons (chapter 10).
They also had some advice, for reading through Leviticus: Unlike many other books in the Bible—or all of them, for that matter—you often don’t want to read through Leviticus paying careful attention to the details. Instead, you might want to look at the “big picture:” how would a particular law make the Israelites different from the nations around them? Why would God want them to be different in those ways? Since I’m not an Israelite, I don’t have to remember all of the dietary rules they had to follow; on the other hand, I can learn something about God’s nature by reading these rules, regulations, and commandments.
To get a more well-rounded understanding of who the LORD is, you should read Leviticus and then read Hebrews, in the New Testament. Leviticus gives us, in painstaking detail, a picture of how Holy God is, and how He must not be lightly approached; Hebrews outlines why the New Testament system of faith in Christ is superior to all of the sacrifices prescribed in Leviticus.
All of the rituals outlined in Leviticus are just that: rituals. They couldn’t save the Israelites from their sin; only Christ could do that. But without the book of Leviticus—along with Exodus, Deuteronomy, and Numbers—and all of the regulations outlined therein, we would not have a complete picture of the holiness of God.