The campaign concept is a simple one - a ship and crew, doing quasi-legal and illegal work, skirting around the edges of civilization. There are a few things that you must keep in mind during character generation. These are detailed below.
The Question That Drives Us
"It’s the question, Neo. It’s the question that drives us. It’s the question that brought you here. You know the question, just as I did."
-Morpheus, The Matrix (1998)
Why does your character live this vagabond life? Characters must have some reason that they are willing to spend some chunk of their lives aboard a ship, with no fixed abode to call home. Are you on the run from enemies? Afflicted with wanderlust? Out to make your fortune and then retire to comfort? Uncomfortable with large crowds? Just nowhere else to go? Any and all of these reasons are appropriate, but you must have an answer for why you live on a starship, eking out a dangerous marginal existence on the edge of space. Use the "Serenity Crew Questionnaire" (see "Game PDF and Rulebooks") to figure out your PC. I will award bennies - extra plot points, maybe extra character points, for a properly completed questionnaire.
Character Generation Specifics
Characters will be "Veteran" level of experience. This will allow you to take on challenging adventures, without ever running out of things too big to chew in one bite. Character advancement is detailed in the Core Rulebook (see "Game PDF and Rulebooks"), somewhere around p. 47. Get one of the character sheets at the same section, and you will find the process almost does itself. Almost. If you print out and follow the one page "Serenity Character Creation" handout (see "Game PDF and Rulebooks"), it pretty much does build itself.
The ship's owner might be one of the PC's, all of the PC's, or even some powerful off-screen patron. There are a variety of options available for the specific type of ship, depending on the size of the crew, ranging from the ubiquitous "Firefly", to Traveller-inspired designs like the "Beowulf", the "Empress Marava", or even larger designs like the "Betty" or the "Thorez". How the PC's come into possession of the ship will be a story on its own. The campaign will have the following minimum character slots, with overlap and redundancy possible:
Captain - Leads the crew, there can be only one. May or may not be the ship owner, might even be a pilot.
Pilot - Flies the ship, usually only one, plus a possible co-pilot.
Engineer - Keeps the drives running, usually only one, assisted by the mates.
Mates - Do all the other stuff, there can easily be two or three of these on a typical scummy little freighter.
No person is an island... we all have people we interact with. If you create NPC's that I can work into the story, I will be grateful and play will be more interesting. Use the "3x3x3" handout (see "Game PDF and Rulebooks") to develop a smattering of allies, enemies, and contacts. I will award bennies - extra plot points, maybe extra character points, for a properly completed 3x3x3 sheet.