Understanding the chronology and genealogy of the Book of Mormon can be difficult, especially if it's only your first or second time reading through it. In a couple sections there are multiple people that write only a sentence or two. And further on in the book there are multiple sections that were written at the same time, but in different places by different people. To help you understand who wrote what chapters, and when the chapters fall into place I wrote a page titled 'Book of Mormon Genealogy.'
My page I mentioned above:
Book of Mormon Genealogy
If you have never read the Book of Mormon, or maybe you have but don't own a copy of it, follow the link below and you can get a free copy of this book.
The Book of Mormon