Middle Earth Adventure game is a well-done free RPG for games set in JRR Tolkien’s Middle Earth. The system is able to be adapted to many of the existing commercial Middle Earth RPG supplements, such as ICE’s MERP.
Games Workshop’s Lord of the Rings battlegame boxed sets come with some bits of terrain to get you started. This page has some paper buildings for Rohan and Gondor to keep you moving along.
Wilderland is a set of free wargames rules for skirmish games set in J.R.R. Tolkien’s Middle Earth.
De Bellus Middle Earth is DBA variant for playing wargames set in JRR Tolkien’s Middle Earth.
Middle Earth are a set of free wargames rules for skirmishes in JRR Tolkien’s fantasy worlds. The set includes specific rules for battles in the three “Ages.”