The battle of Cynoscephalae in 197BC pitted Greek phalanxes against Roman legions. This scenario recreates that battle for the Vis Bellica rules set.
My friend Jim loves to run dreadnaught era naval miniature wargames. Here’s a good scenario for the Battle of the Yellow Sea from Bill Madison of the Naval Wargames Society.
Niagara 1814 is a scenario book for Blackpowder. As with any book of scenarios, however, they can be adapted to whatever rules set you play
Gnome Stew has an interesting form to help you plan gaming adventures. It gives the game master a place to record locales, story goals, adversaries and treasures. It is intended for role playing, but I think it also would be useful for those story-driven miniatures skirmish games.