The Blue Mule website has a pictorial record of some of the early figures in fantasy gaming. I'm showing my age, but I remember a lot of these figures from when I was in high school and college.
Here are some rules for using the Dirtside II system to recreate battles from Heinlein's Starship Troopers.
The Heavy Metal Wargaming site has some counters for use in starship games set in the Star Trek: The Next Generation universe.
Wargamer and Teacher Matt Fritz has written MiG Madness, a set of free wargames rules for playing air combat in the Korean War.
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.