Reddit reviews Mormonism: A Very Short Introduction

Though you didn't ask for this, if you want a brief account of Mormonism I would suggest Mormonism: A Very Short Introduction by Richard Bushman. The book is very good, and though there are many good books to suggest, if you didn't have a lot of time to read a ton of stuff I would read this.

And of course, I would encourage you to read the Book of Mormon as well. Where to start? To be honest from the beginning. The book is largely a chronological story and so I would start on page one.

If you're looking for a one-volume general history, I'd recommend either Matthew Bowman, The Mormon People: The Making of an American Faith (Random House, 2012), or Richard Bushman, Mormonism: A Very Short Introduction (Oxford, 2008).

You might find the Encyclopedia of Mormonism useful to look up unfamiliar concepts. Being published in the 90s, it's admittedly somewhat out of date (they need to publish a second, revised edition), but the whole thing is online, so it's a massive resource that's easy to access.

The Third Book of Nephi. It has the thematic climax of the book where Jesus Christ appears to people on the American continent and establishes his church there.

I usually recommend Oxford's "A Very Short Introduction" series to people who want to learn more about Mormonism or The Book of Mormon, but who are not necessarily interested in conversion. They're short, like 100 pages, and scholarly though written by believers.

The Oxford Short Introductions Series has a great volume on Mormonism that covers the faith in a very even-handed and neutral manner. If you're pressed for time, this would probably be the best thing to read. The Dummies and Idiot's Guide are actually not that bad in their presentation of the faith; they're both by what would be termed "liberal Mormons" and do a pretty good job of being realistic in their presentation (though both still being very positive, of course, but they're not conversion texts).

To understand the different faiths in the Latter Day Saint movement you need to understand the history of the faith as so much of the faith claims are rooted in historical events. Books like Rough Stone Rolling and No Man Knows My History give a good overview of Joseph Smith's life. The upcoming Brigham Young biography by John Turner seems like it will also be a good source for information on Young's tenure as president of the Church as it will discuss some of the darker/stranger issues like blood atonement and Adam-God. If you want to go in depth on the history of the Temple ritual, I'd recommend Buerger's The Mysteries of Godliness.

The last information I would give is that most (but not all) books published by Christian publishers should probably be avoided. Nowadays most of them are factual in their content, but their presentation is not meant to provide an understanding of the LDS Church but rather is meant to provide a multiplicity of reasons not to associate with the faith. A few exceptions I'd say are most books by Sandra and Gerald Tanner, and By His Own Hand Upon Papyrus which is an amazing overview of Joseph's "Book of Abraham" and the history and implications of the papyri Smith used in producing it which were rediscovered in 1967 to the subtle consternation of the CHurch ever since.

Mormonism: A Very Short Introduction by Richard Bushman. Part of a series by Oxford University Press that tries to concisely summarize a variety of complex topics.

For something more in depth, but hitting all the bases you described quite well, I highly recommend the The Oxford Handbook of Mormonism. Seriously if you read that, you will come away with a very in depth understating of Mormon history, theology, culture, practice, and experience. But it is very long.

Oxford has also published a great book on the development of LDS theology called Wrestling the Angel.

Matthew Bowman's The Mormon People is also very good and has been used as a textbook in university religious studies introduction to Mormonism courses.

I think this is a good primer.

https://www.amazon.com/Mormonism-Introduction-Richard-Lyman-Bushman/dp/0195310306/ref=sr_1_2?s=books&ie=UTF8&qid=1536140911&sr=1-2