This tiny and simple printable papercraft model allows you to create your fleet of space freighters with a feel of the popular scifi series. I didn't plan the model for public download - sorry if there are any inaccuracies, I tried to clean up the sheet a bit.
As modelling hints, you should perhaps use a metal ruler and snap-blade knife (and be careful with those!) and use a sharp pen to draw folding lines on the blank side. And test that everything fits before applying glue.
Follow-up: If you want to print various freighters, you can find Adrian's sheet compliation with c3, c8 and c16 models at http://www.macs.hw.ac.uk/~adrian/b5/freighters/b5-like-freighters_modified.jpg