"Saints" is a palatable book about the origins of the Church of Jesus Christ of Latter-day Saints. It is published by that church and members are encouraged to read it. It starts with an explanation of the year without a summer.
I am an active lifelong member, so take that into account when evaluating my opinion. But I think that this book would be a worthwhile read to anybody who is curious about the origins of Mormonism but not necessarily interested in joining. Yes, it's written by proponents. But I think it is objective enough to be worthwhile.
Oh, and Volume 2 was just released. Oh, and they are available for free. Even from Amazon.