Original meaning
Originalists of all stripes cite "The Federalist Papers". It is fairly tenuous to suggest that this represents a good source for the original "intent": after all, Alexander Hamilton, who wrote the majority of those essays, was absent for the greater part of the Philadelphia Convention, and John Jay did not attend it at all. However, James Madison, the principal framer of the Constitution also wrote a substantial amount of "The Federalist Papers". Also, to suggest Hamilton and Jay's absence from the convention implies their ignorance as to the Constitution's original meaning is demeaning to those two men and inaccurate. The collected anti-Federalist papers, of course, will be no use at all to a person searching for the original "intent" of the framers. However, as evidence of how a reasonable person at the time would have understood the words of the Constitution, "The Federalist Papers" and the anti-Federalist essays are evidence of direct relevance.
The Federalist Papers
"The Federalist Papers" (specifically Federalist No. 84) are notable for their opposition to what later became the United States Bill of Rights. The idea of adding a Bill of Rights to the Constitution was originally controversial because the Constitution, as written, did not specifically enumerate or protect the rights of the people, rather it listed the powers of the government and left all that remained to the states and the people. Alexander Hamilton, the author of Federalist No. 84, feared that such an enumeration, once written down explicitly, would later be interpreted as a list of the "only" rights that people had.