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.
Anti-Federalist Papers
Considering their number and diversity, it is difficult to summarize the contents of the Anti-Federalist papers. Generally speaking they reflected the sentiments of the anti-Federalists, which Akhil Reed Amar of the Yale Law School generalized as: a localist fear of a powerful central government, a belief in the necessity of direct citizen participation in democracy, and a distrust of wealthy merchants and industrialists. Essays with titles such as "A Dangerous Plan of Benefit Only to The 'Aristocratick Combination and "New Constitution Creates a National Government; Will Not Abate Foreign Influence; Dangers of Civil War And Despotism" fill the collection, and reflect the strong feelings of the authors.