Glass as in glass that will be transparent and have geometry behind/beneath it?
The main thing with that at this stage is to simply make it a separate object from the rest of the model. Once your model and textures are done and you're ready to convert, you re-attach the glass object to the main mesh in Truespace before saving. What this does is ensures that the glass polygons are last in the list to be rendered in-game, so the transparency works properly and the glass doesn't hide parts of the ship beneath it.
As for the details, you'll have to use your judgment. Here are the three main options though:
1) Geometrically attach or integrate detail on to your mesh. This is the most common method and should be used on most medium-large scale details.
If something is
geometrically attached to your mesh, clicking any single verticie on either the mesh or the detail and pressing ctrl + L should select all verts in both parts.
As long as there are no holes (missing faces, disconnected verts etc), this is the most stable type of model during conversions and in-game.
Example:

2) Have your detail as a part of the same mesh, but the pieces themselves are separate. Ie, if you select a vert on the detail and press ctrl + L, only the verts that make up the detail will be selected.
This is the method you should use for small details like pipes and stuff where it would be a waste of polys to geometrically attach them.
This method is usally quite stable as long as you keep the separated objects relatively simple. If you begin building huge chunks of hull out of separate pieces, it will most likely cause problems somewhere along the line.
Example:

3) Have your detail as a separate mesh from your hull mesh entirely. Use this method
only where you want the game to recognise the detail as a separate object, such as a radar dishes, turrets, rotating subsystems or detail boxes (basically detail that will only be drawn when close to it).
Whatever you do, don't use this method to build your ship's hull out of separate objects, because this would get you the least stable and probably a PCS crash-happy result. I can explain this in more depth if needbe - it has to do with Truespace and PCS.
Example:

So yeah - just pick which type you want to use based on what type of detail you're trying to achieve.
Raven: I didn't know you used Blender? Awesome.

(though you might want to look up the mirror modifier in the edit section of the buttons panel - it'll mirror everything as you go rather than you having to use the mirror tool (m), and once you apply it you don't have to remove doubles

)