Well, I'll assume that you're completely new to texturing, so I'll explain the process in that level of detail. If you already know some/most of the stuff, then just skip over it, but if you don't, it's very handy to know how the system works.
Ok, there are 3 basic components involved here: the geometry itself, the UV map, and the texture.
The geometry is just a number of connected faces (usually triangles) that form your mesh. The texture is a just a regular image. The UV map is what defines _how_ that texture image is to be applied to the geometry - sorta like your wrapping technique defines how wrapping paper (ie, a 2D image) is applied to a present (ie, 3d object).
The simplest (easiest but usually the worst looking) form of UV mapping is called UV projection in Truespace. It basically maps your whole object in one go. The button(s) look like this:
in Truespace. Click and hold to bring up the little list of tools you can use as shown in the pic above. Clicking any of them will apply that type of UV projection to your entire selected object - it will overide any and all existing UV projections/mappings, and cannot be undone. (SAVE OFTEN!!!!)
To use this method, first select your ship and apply whichever projection seems to overall suit the shape of the ship. To set this projection, click the mouse icon.
Now you need to apply some actual texture(s).
Open up the material editor:
and then open up the colour pane (the one with the red line showing it's button in the above pic).
Right-click the colour pane (which should initially appear as a colour selector), and from the "Colour Shaders" window that pops up, choose the caligari "texture map".
Now you can right-click the colour pane again and select an image you want to use as a texture.
To apply this texture to your model, you use the three tools shown on the left of the material editor - flood fill on top, and paint-face and replace sharing the second place (click and hold the button to bring up the list of tools, just like the UV projection tool).
Using the paint-face brush, you can paint individual faces with a currently active texture. This is allright to start off with, but you'll soon find that you need more projection flexability.
Now, the most advanced form of UV mapping is UV unwrapping (a good tutorial for this can be found here
), which involves manipulating the UV projections of individual faces or groups in a program like Lithunwrap, but you'll most likely want in intermediate step to warm up to that level.
Remember how you applied a UV projection to your whole selected ship? Well you can do the same thing to individual selected faces, and even better, groups of selected faces.
To select faces/groups of faces, right click your model, hold ctrl, and select all the faces that you want to apply a certain type of projection to. Planar usually works best, but it's up to you and what you're selecting.
Again, applying a UV projection to those faces will overide whatever the main projection is for them, but it will only do this for those particular faces. It is also still not undoable, so SAVE OFTEN!
You can also manipulate the projection you select by the box frame thing that appears around your selected faces:
While this doesn't quite match the flexability and raw efficiency of UV mapping in Lith, it is a fairly good way to learn the concept.
Finally, remember not to use too many textures on it overall, as every additional texture on your ship will degrade performance overall.