Thanks guys. And yep, exactly as Flying Steel said.
The diffuse texture for this is actually quite drab. The metal effect is almost purely the result of a good specularity map.
Most new texturers try to cram everything into the diffuse map, as far as actually making almost all of the textures from photos. That's not quite the way you do it and the results are often quite bad. Metal textures don't exactly look like metal if you attempt to purely use a phototexture.
Most game models now have multiple maps that work together, not just one (although I have no idea which are supported by nexuiz currently). It's important to make them correspond, like the edge of a panel in the bump map should fit the edge of the panel in the diffuse map and the spec map, the shadows of the diffuse map should correspond with how high they are in the bump map, etc. (hence why working with a masterfile is highly recommended rather than doing each map separately). I'll try to outline them here and give samples from this model (Note that these are still not finished maps, but can already show you the basics of how they actually work in concert. I resized them for this thread. Also once I finish I will provide a PSD file to show you the basic workflow):
Diffuse/Color Map - this is what people usually refer to when they say texture. As the name implies it's simply the color you put in the faces of the mesh. And by color I don't mean monochrome, but fullblown textures. Like the wood grain photo you might put on a tree mesh, or a picture of a leaf you might put over an alphad mesh of a leaf.
Luma/Glow/Self-Illumination Map - Determines which areas of the mesh remain continuously lighted no matter if it's hidden in shadow. The values are simple: Black means it's affected by dynamic lighting etc. and will not glow in full shadow, the lighter it is the more it will 'glow'. White = glows, Black = does not glow. It's important that it corresponds with the diffuse map too, since it illuminates any area no matter if it's just metal. So placing a patch of white on a glow map where it is actually just metal in the diffuse map would result in a weird always visible patch of metal on your final model (although that will also be useful to show diffuse lighting, like a continuously illuminated sign under several lights).
Bump/Height Map - Determines raised/recessed parts of the model. White = raised, black = depressed, and all values of gray in between. Bump maps are usually quite smooth in metal (no pitting unless it's organic), with sharp edges unless you want it to have rounded corners. Bump maps however are a bit limited in comparison to normal maps, but you can convert bump maps to normal maps with certain plugins and apps easily enough.
Normal Map version of the above Bump map (a bit more complex to explain than bump maps so I won't try ;D it works on a similar concept to bump maps except that it relies on how light bounces off a specific area in the face):
Specularity Level Map - Determines what areas are shinier (i.e. turn white when illuminated directly). The combination of spec and diffuse often is what makes something recognizable metal or glass or rubber. Hence you can make a fully black diffuse map for a box, use pure white for specularity and end up with a glassy cube. Or you can use a gray diffuse map for a box, and use a speckled, streaked, rusted etc. specularity map that are a bit more worn around the edges and up with a metal box. Or you could paint the box black for diffuse and use an almost black spec map and end up with a rubber box. etc.
Anyway, le progress:
Still have to refine the textures further and add masks for 'shirt/pants' color. A word of warning: I know nothing about animating. At all, not even setting up bones and whatnot.

So I'll have to leave that part up to you guys. As for the 'horse legs' I thought one of the nexuiz models already had horse legs.
