Please have your scriptures and The Lectures on Faith for the upcoming Idaho Falls lecture.
Elder Christopherson of the Twelve gave a speech at BYU Idaho this week. It fits in nicely with the upcoming talk, therefore I am linking it here. I'd recommend you listen to it. His defense of the Prophet Joseph Smith is needed as more and more believing Latter-day Saints get a little troubling information, and collapse in disbelief. The cure, as Elder Christopherson explains, is to not know too little, but to immerse yourself in study and find the answers to any troubling information you unearth.
We have greater access to information today than we have ever had. But if we neglect studying it, then it serves no purpose. Whether Joseph was a prophet or not should matter to you. If you conclude he was, then he affords an opportunity to better understand the relationship between God and man. Joseph's life is recent enough, with sufficient enough material, that we can learn things about him that are not available to us about Paul, Peter, John the Baptist, Mormon, Moroni, Nephi, Isaiah, Moses, Abraham, Noah, Enoch or Adam.
Learning of the difficulties Joseph endured, understanding the tendency to attribute ill-will to his words and actions despite what motives were in his heart, and the subsequent drift away from his preaching and teaching is important to understand. That understanding should help you in your own effort to live in harmony with God.
I believe that the many revelations in the D&C identifying Joseph as the spokesman for God means exactly that: Joseph was and IS the spokesman God sent. Joseph's words need to be heeded as if they came from God directly to us. No one has the right to change or ignore them. No one (and I mean NO ONE) has the right to claim they are Joseph's equal. There are no "keys" or "key holders" who can alter Joseph's teachings except at their peril. When they ignore or contradict Joseph's revelations, and teach others that they can ignore the message and warnings given by that prophet who was called by God to begin this dispensation, they damn themselves and any who listen to them.
When Elder Christopherson defends Joseph, I want to rejoice and shout my own "Amen!" to his message. He is my brother in belief as he makes that defense.