In 2007, I bought Richard Lyman Bushman's Joseph Smith: Rough Stone Rolling. I was a little afraid of it and didn't read it at first. After all, I was vaguely aware that there were some crazy things in Joseph Smith's history and I wasn't sure I wanted to know them. Eventually, though, I decided that I couldn't ignore unpleasant things forever.
And it wasn't that bad. For many of the more-controversial issues, even when we know (or think we know) the fact, we know less about the context and even less about the reasoning. Now, I'm not a Mormon studies scholar (if I was, there'd be a job waiting for me at the Maxwell Institute (Zing!)), but I think that, since 2007, I've read more extensively in Mormon history than the typical member and I can tell you that there's nothing I've come across that made me question my testimony of the truthfulness of the restored gospel of Jesus Christ. But I'm aware that for some people, this isn't the case. When they find out something troublesome about the life of Joseph Smith or Brigham Young, they sometimes have trouble rectifying that with continued involvement with the church.
A book that helped me understand this a lot better was Shaken Faith Syndrome by Michael R. Ash. The first half of the book explains that many people's problems with troubling items don't come from the item itself, but from the feeling of deceit and betrayal they get. "How could they have lied to me?" or "What else aren't they telling me?" is what leads them away, not "I can't believe that dude had so many wives!"
This pointed out to me the importance of teaching correct, unvarnished history to my friends and family, and of the duty to learn for myself. It gave new meaning to Hosea 4:6 as I watched my relatives leave the church because they had done a poor job reading their Gospel Doctrine lessons. (It's amazing the number of items that "the Brethren don't want you to know" that have actually been included in Gospel Doctrine manuals for years.) We had a Family Night lesson where we made sure our kids understood that Joseph Smith practiced polygamy. Our kids said their Primary teacher had explicitly told them just the week before that he did not. We've since had Family Night lessons about translating by looking at a stone in a hat while the plates sat off to the side under a cover. (About this issue I once read, "If you were a scholar, then you knew that Joseph used a seer stone. If you were a regular Church member, then you knew that Joseph used the Nephite interpreters.[p.180]" A woman makes model golden plates for kids with stone-in-the-hat depictions shown on them, available here.)
It reminds me of a story I believe I've shared before: I'm all for new-age "you are a special snowflake" parenting, except for when it's dangerous. So before my kids knew how to swim I would tell my kids, "You can do anything you want, except swim; YOU CAN'T SWIM!" And my kids would say, with typical kid bravado that turns a half-assed attempt into accomplished proficiency, "I can swim," and I would get in their face and tell them, "YOU. CANNOT. SWIM. You can drown, but you can't swim."
Now, why was I being a jerk to my kids? (Aside from the obvious reason of "because you're a jerk to everyone"?) Because if my kid scribbles on a paper and thinks he's drawn a masterpiece, meh, no harm done. But if my kid thinks flailing in water is swimming, he will die. (One time at the pool with my brother's family, his daughter just was all, like, "La-dee-da, into the water," and had to be pulled out by the lifeguard.) Anyway, it turns out that misunderstandings about church history are as important to set straight as whether or not a kid can swim. Because if your kid gets his Book of Mormon knowledge from the Arnold Friberg paintings, he's going to have troubles when he learns that Mesoamerican cities didn't have 80-foot-high walls and the Armies of Helaman weren't extras from the battle sequences of the film 300. "Sword" and "horse" might not mean what he thinks they mean. "Nephite coinage" is a term that only appears in a non-canonical chapter heading. Many of the book's grammar errors aren't actually errors at all (and Moroni gives a smirk and a nod). Official Declaration 1 wasn't as absolute as it is sometimes presented to be.
The second half of Shaken Faith Syndrome is a great reference for faith-assuring answers to troublesome questions regarding church doctrine or history. Much of that material is also available at FairMormon.org. If you wished FARMS hadn't wasted away to nothing, you should check out Interpreter. And maybe someday, if there's any reader interest, I'll share the list of Mormon blogs I follow. The point is, you've got to learn, but learn from faith-building sources.
So my advice to those who are reading the gospel topics essays or finding things out on Wikipedia (at least have the common sense to not research topics on Exmormon.org, okay?): settle the question with some research in official church publications and from sources that attempt to answer your questions while not undermining your testimony. Then, when dealing with the "betrayal" feelings, recognize that the fault was partly yours (for not studying fully), partly your parents (for not teaching you correctly), partly your fellow members (for not magnifying their teaching callings), partly your local leaders (for not ensuring strong gospel teaching), and partly church leaders (for not prominently including difficult topics in the church lesson curriculum), but it was never a matter of willful misleading or betrayal. No one was lying to you, even if what they were saying wasn't true. Please forgive, and work to make sure you can help stop the ignorance that threatened you from spreading.