This is a little project I did last summer, to develop my modeling skills. For a long time, it was just sitting on my hard drive, but after a request for the file on Google+, I decided I may as well share it here.
The objects/materials are named appropriately, and organized into layers (armor, command tower, turrets, etc). The turrets are rigged to pivot and track targets, and everything is parented to an empty named "Venator", for easy animation.
Textures were hand-made in GIMP, some of them I made by tracing over the UV layout. I also made the planet in GIMP, but the space backdrop is a NASA image.
The scene is set up to get the preview image by default, just open the file and hit F12.
Layer 1: Edges / side hangar bays
Layer 2: Main plating
Layer 3: Center ridge / main hangar
Layer 4: Command tower / lights
Layer 5: Detail thingies :)
Layer 6: Engines
Layer 7: Turret wells
Layer 8: Turrets
Layer 9: Bombardment cannon
Layer 11 has some "greebles" for the main plating; but they are disabled in the render, because they turned out to be superfluous. I included them anyway, though, because some of you might want to play around with them.
Layer 12: Side guns (actually from Greyoxide's excellent "Shipyard", v0.5 I think)
Layer 17: "Greebles" for the turret wells
Layers 18 & 19: Lamps, for the engines and hangars
Layer 20: Cameras and scene lighting
Hope this file is useful to someone, and Happy Blending!