The book of Leviticus originally formed part of a larger whole comprising what are now the first four or five books of the Old Testament. Its name is descriptive - 'the Levitical book' being about the personnel of the temple, all of whom were supposed to be descended from Levi. In one way the description is accurate, since the material was produced among the priesthood which had survived the fall of Judah to the Babylonians in 587 BC as a manual of instruction for its members. However, since priests in Israel gradually emerged as leaders of the nation, the book of Leviticus is also directed at the laity and, by the promulgation of laws set in a historical narrative, intended to instruct them in their religious and civil obligations.
I'm going to be really sad if the library doesn't have this entire series, because they're incredibly helpful as a way to understand the background of the formation of the Old Testament.
This guide gets 4 stars for explaining how the text was strongly influenced by writers after the first exile, pointing out repetition comes form merging various splinter groups around Jerusalem, whose traditions varied, and how the text interacts with later books of the Bible that were likely written around the same time. It was essential in helping this be more than a boring list of laws that are effectively erased for Christians, other than their general guidelines not to be horrible people.
Leviticus itself? A total slog. I can't say that I'd read more than a few passages here and there, and now that I've finished, I can't imagine I'd ever read this one again. When I go back and re-examine other books, Leviticus itself is totally at or near the bottom of the list. But if you need a book to help you with understanding why it came to be (although not why it might still be important, which is for other books to explain if they can), I definitely recommend this one.