This tutorial shows how to make modular cave tiles that also serve as hills for wilderness games.
Making Flocked Magnetic Unit Stands
The WAB Corner Blog has a nice post on making terrained magnetic bases to hold four figures based individually on washers.
From Lexington To Yorktown AWI Rules
From Lexington To Yorktown is a set of free wargames rules for American Revolution battles. Each model equals 10 infantry.
Advance To Cover World War II Rules
Advance To Cover is a set of free wargames rules for World War II battles. The scale is battalion level where one figure = one section, or company level, where three figures = one section.
Medieval Skirmish Rules
Lord Merlin has a set of free wargames rules for large (70mm or 1:20) scale figures. There are three levels to this skirmish rules set: “simple”, “better” and “more realistic.” There also are some cute pictures of a “knights of the dinner table” game.