UV mapping is a complex job, and can easily take as much time to learn as modelling itself. Ideally, I'd say you should get Ultimate Unwrap and UV all 50 models, then go back and start over - using the initial UV jobs as practice so by the time you've done them all you'll know what works and get a good work flow going.
I use Ultimate Unwrap but you should be able to find the old Lithunwrap for free - very good UV mapping software. Ultimate Unwrap shows you what you are UV mapping on the 3D model and UV map, it solves so many issues that can confuse the hell out of people when learning. I strongly suggest buying it if learning this stuff quickly is a concern.
This of course assumes that you can draw textures already, or at least have good skills in an art package. If not you should try to learn this as well.