What does the Church of Jesus Christ of Latter-Day Saints teach about who Jesus is and where He came from?

From the answer to another question , someone suggested that the LDS (Mormon) church teaches that Jesus is distinct from God—that though He is a part of the Godhead, the Godhead is not a Trinity defined by the "Three-in-One" idea. What specifically, then, does the LDS Church teach about who Jesus is and where He came from? Is He eternal, not eternal, uncreated, created?