Against the Scourge of God is a set of rules and a scenario for replaying the battle of Chalons. At Chalons, Romans under Aetius and Visigoths under Theoderic turned back an invasion of the Huns.
The Wargame Terrain blog has a nice tutorial on making a thatched hut native village.
For many years, George’s Nafziger’s collection of orders of battle for conflicts dating from the 1600s to the 1900s have been a mainstay of the historical wargaming community.
Once available only commercially, Nafziger recently donated his collection to the Army’s Combined Arms Research Library.
Champs de Bataille is a set of free wargames rules for ancients based on DBM. Each unit represents 125 to 250 cavalry or foot; more if a warband. The game is designed to be played on a hex board.
Link (direct download)
Here’s a nice tutorial on making insulation board hills for your wargaming table.