Wow, thanks guys! That's a lot of good info.
I downloaded several of the programs and since Anim8or looks the least intimidating I've been using it as a starting place. I can see where Blender certainly looks to have more features, but I'm guessing the basics are fairly common.
So far I've managed to get the most basic shapes of my ship, the wings and the main fuselage, built to what looks like about the right scale and position to each other. I'm setting it aside until this weekend when hopefully I'll have some time to go through some tutorials for either Anim8or or Blender. So far it's been easy because it's all been a matter of using the basic shapes in the software and adjusting their size, scale, and position, but from here there's some fairly specific stuff I want to do that I'm clueless on.
One thing I'm curious about since most of you model ships that have already been designed is how do you make sure your model is accurate? Do you measure angles and proportions on line drawings? What I'm trying to do is so much simpler because I can just eyeball it and say "Yeah, that looks right." I'm just blown away by how people do the really accurate models of more complex shapes like any of the Enterprises. Simply amazing.