[Note: All these links are offsite. If you have any concerns about their content, contact the webmasters of those sites.]
To Those Who Are Investigating "Mormonism" This is the single best one-page introduction to the LDS church (and its surrounding controversies) on the Internet. It's the site I always recommend to those who are new to this religion.
JosephLied.Com A straightforward, hard-hitting examination of some of Mormonism's major difficulties. Well worth a visit.
The Anti-Mormon Preservation Society This site contains online transcripts of books written by people who actually lived and breathed during Mormonism's controversial early years. As such, this site makes for very interesting reading.
Mormon Scripture Studies This is a wholly scholarly site that gives "just the facts, ma'am." LDS-related scholarship quite simply doesn't get any better than this.
The Best (and worst) of Mormonism Information about a lot of subjects relating to Mormonism. If you're looking for anything at all, it's probably here!
Notes on Bible Problems I can't possibly recommend this page enough. If you're finding your way out of Mormonism, remember that the same standards of critique should be applied to the rest of Christianity as well. After reading this page, you'll know more about the Bible than 99% of professing Christians. Another good resource can be found here.
A Close Look at Mormonism This site offers valuable information on Church history and the life and character of Joseph Smith.
Questions to Help the Assessment Process Here you'll find questions to ask yourself about a religion to keep from being deceived. Another good page by the same author is Mind Control - the B.I.T.E. Model. Although he isn't singling out Mormonism, the parallels in both pages are downright eerie. For a quick summary of the same issues, read this.