There's no one tutorial for this, mainly because it covers a wide array of skills you need to master. To get a ship in the game, first you need to learn to model, uvw map and texture. These are general art skills and you can't just learn to do this for TBP - you need to learn it in general. There's a lot of tutorials about this out there, depending on your apps of choice but ultimately there's no quick fix - you need to take your time and develop your skills by getting loads of practice. So, if you're interested in learning 3d modeling, I would suggest choosing a 3d app, googling for some tutorials for said app and starting with that. I personally use 3ds max, though that app is pricey so you might try a free one first, such as Blender. Once you've mastered modeling you can move on to uvw mapping and texturing.
Of course if you just meant converting existing models, that's different as you can skip the very long first step of mastering the 3d art skills. There are two conversion methods I know about, one is using the buggy 3ds max converter that only works up to version 8 of 3ds max. This method works but you do need to get the ship through PCS2 before it's usually ready for the game. The other is using collada and the PCS2 version that supports dae import.
Both of this methods would be better described in detail by someone else, however.
