i've found, as i started some months ago, extremely useful this tutorial:
http://underworld.fortunecity.com/pacman/106/fs2mods/shipcreationguide/shipcreationguide.html actually the site is down due to fortunecity maintenance (mine is down too...) and i can't remember who created this guide but in the same site there were some galactica-mod pictures...
check it in the next days, maybe you will find it online again..
there is also the tutorial of sandwich somewhere but i haven't added to bookmark the link so i can't remember where it is(i don't have rhino and it was rhino-centered....but it may be useful anyway..)
this two plus the one at volition watch that thorn reported are -as far as i know- the only "how to model a ship that will work on fs2" guides that i found...they may not completely cover all the stuff...but there isn't so much else, and you will be able to see the missing parts on your own
bye
