And my players want to start out as Pirates. I was wondering if it would be a good idea to have them reporting to a higher boss at first, until the the Imperium cracks down on their base while they are gone, forcing them to find a way to struggle on their own.

Since this is my first time GMing (my first time really playing an RPG as well), I was wondering if there was any tips you could give me for running this kind of game well. What kinds of things could I do to motivate the players to continue, how should I manage the near limitless freedom being totally outside the Imperium would bring? ect. ect.

Sounds like a good start And while the characters are indeed free to wander free as birds, point out they still need to get their promethium, and food they can actually metabolise, from somewhere - that'll keep close to known space

Well, "Hostile Acquisitions" is just out. While I did not have a copy (the PDF is not on sale YET) I would suggest you wait just a little further till the first
forum user have word-of-mouth if any good rules for pirates are found in their.

Hostile Acquisitions introduces some particularly devious options for players and GMs. Characters gain alternate career ranks, such as the Swashbucker, the House Operative, and the Cold Trader. These new alternate career ranks are highly flavourful, and allow you to make a character with a distinctively “scoundrel” bent. GMs can craft custom adversaries for their groups with the Nemesis Origin Path. You'll also find gear and starship upgrades to facilitate piracy and smuggling, a section on Imperial adversaries and details on Imperial Law, guidelines on how to run a “con” game , and a list of mythical treasures waiting to be “liberated.”

...if the conntent keeps what the advertisement text promises it seems you should get a copy

Thanks Drhoz, I can't believe that I forgot about things as simple as promethium, hah. And Gregorious, consider "Hostile Acquisitions" on my list.