I have read a fair amount of Mormon history, and some of the Book of Mormon, and it's a bunch of racist bullshit. Joseph Smith is one of my idols, not because I believe he was an enlightened savior, but because he was able to have sex with as many women as he wanted (It did come back to haunt him though; his first wife left him upon discovering his other wives). He also had a loyal band of followers that followed him across the country and did his every bidding. Many of the original practices of the LDS Church are no longer PC, so they have been trying to modernize and improve their image, however this does cause conflict between those who consider Joseph Smith to be entirely right and those who don't (ei Colorado City).
A central part of the Book of Mormon is the idea that the Native Americans are actually a lost tribe of Israel, turned red for sinning. Of course, all genetic and archeological evidence supports a slow migration across Northern Russia as the means of populating North America.
The biggest problem I have with Mormonism though is it's history. The Catholic Church has committed horrible, horrible atrocities, but they originated more than a thousand years ago, when science was more or less logical philosophy and mathematics. The Mormon Church originated 150 years ago and has been responsible to the Mountain Meadows Massacre, isolated colonies of polygamists (who literally banish competitive males because the gender balance is disturbed), and an open denial of basic genetics. The Catholic Church has stifled science before (and arguably now), but the Jesuits invented the model for the modern university.
I am not going to proof read what I have just wrote.
I'm a functionalist and a pessimist.
Anyway, I encourage you to Chat with a Mormon on mormon.org, its extremely entertaining...