Skeptic's Annotated Bible is an annotated Bible intended for the use of atheists and skeptics. It is maintained by Steve Wells. It also contains an annotated Koran and Book of Mormon. It's a useful resource which shows why it's not reasonable to believe the Bible.
The Skeptic's Annotated Bible republishes the King James Bible, later Bibles may be copyright. Beside each text are commentaries explaining why sections are unreasonable, unjust, cruel or otherwise unworthy. Atheism Wiki frequently links to the Skeptic's Annotated Bible.
The Skeptic's Annotated Bible is effective against those Fundamentalists who claim that the King James Bible is divinely instired and literally true. Other Christians maintain that not all in the Bible is true and the Skeptic's Annotated Bible is less effective against them.  Once people deny parts of the Bible are true it becomes difficult to decide which parts of the Bible should be believed.