I just finished reading Bart Ehrman's book, Misquoting Jesus: The Story Behind Who Changed the Bible and Why
. The title of the book is probably the most provocative portion of the whole book. In fact I refused to buy it for just that reason. The book store is full of fantastical "history" that has no basis in reality (i.e. Holy Blood, Holy Grail and many of the books on the Gnostic Gospels.) This book is not one of those books. However there wasn't much that surprised me either. Maybe that is because my Bible has footnotes that point out variant readings and seperates out whole segments that aren't in our earliest manuscripts (like the story of the woman caught in adultery.) So I am familiar with some of these issues.
There are several types of errors, which are discussed. In Bible class at the Adventist schools that I have attended, we discussed errors that were simply mistakes (skipping a line, mispelling a word, or writing a line twice.) However some of these changes were intentional. Scribes would change the wording so that it made more sense to them and sometimes they would change the wording because they didn't like what it said. For example they would take a text that implied that Jesus was only human and changed it to highlight his divinity.
The book is also somewhat biographical. Dr. Ehrman believed in the doctrine of inerrancy. This belief led him to the study of Biblical Languages and the development of the texts of the Bible. That study convinced him of the error of inerrancy (much to his own surprise.) At this point he considers himself to be an agnostic.
I would recommend the book for anyone who wants to more about the history of how the Bible came to us. You don't have to agree with all of his conclusions about what the changes mean, but it is important that we understand the human factors of how the Bible came to being.