Here’s a treasure trove for you science fiction miniatures wargamers: The Starship Schematics Database has illustrations of hundreds of spaceships form the Star Trek, Babylon Five, Space Battleship Yamato and Battlestar Galactica universes. I think these would particularly useful as a source of illustrations for home made counters for your games.
How big is a Stardestroyer compared to a Romulan D’deridex? Which is bigger, a Vorlon cruiser, or Farscape’s Moya? This great site has size comparisons of the great ships from science fiction.
The Heavy Metal Wargaming site has some counters for use in starship games set in the Star Trek: The Next Generation universe.
The Starmada demo miniature wargaming rules are available from Majestic 12 games:
Starmada is a simple (but not simplistic) board game of starship combat, in which players square off in a general attempt to blast each other’s fleets into just so much space junk. While the universe of the Imperial Starmada and its major adversaries is fully detailed in the rulebook, Starmada is much more than just another game, tied down to its own background. Instead, Starmada can be played in just about any science fiction setting you can imagine. There are dozens of optional rules, exotic special equipment items, and menacing weapons that can be used or discarded at your discretion, to create the type of game you want to play!
Star Ranger has this advice for basing your starship models. There are lessons to be learned here for players of Battlefleet Gothic, Full Thrust, Star Fleet battles, and other science fiction miniature wargames.