I'm curious what version of the book of Mormon is considered the official version? For example, when translating the book of Mormon into other languages, what is used as the "base text"? Presumably if we had access to the original golden plates the translators would use those, but seeing as they are lost, some other version has to be regarded as "the most authentic". Which is it?
The latest edition of the Book of Mormon can be considered the official version. When translating the Book of Mormon into another language:
The two or three people who are selected as translators team up with others in doing the work. They have Church headquarters supervisors, local reviewers, a lexicon for reference,6 translation guides, computer programs, and ecclesiastical support that extends all the way to the First Presidency. ... This doesn’t mean that a translation is perfect when first completed. Often, time and further reviews by those studying the scriptures suggest improvements in grammar and vocabulary or find typesetting or spelling mistakes. Rarely, changes are made in the explication of doctrine. When these are made, they are made under the guidance of the First Presidency.
See the articles Scripture Translation into the Language of the Heart or Every Man in His Own Language for further details on the translation process.
6 The lexicon defines every word in the English scriptures so translators can better understand the meaning of the words. Often, words have more than one meaning, so translators must depend on context, inspiration, and teamwork to identify the right solution. Occasionally, questions about meaning are resolved only by the First Presidency.
depperm is right, the latest edition of the Book of Mormon (published by the LDS Church) is the official version. However, other versions exist and are sold in the 'official' LDS bookstore (Deseret Book). Royal Skousen, a professor at Brigham Young University, has been working for over 20 years on a project to recover the original, or earliest, text of the Book of Mormon. In other words, the text that Joseph spoke as he translated from the golden plates. The culmination of that work can be found here. Also, this link is a nice explanation of how Skousen's version differs from the current 'official' LDS version.