BH is a pretty good class to wipe out Jedi. Keep your distance at first, while avoiding running. Focus on draining the Jedi's Force points by shooting at them accurately. Once they're out of FP they won't be able to block your shots anymore. You could try landing a poison dart as well, which will halt the Jedi's FP regen. When the Jedi gets close, let go of your walk/crouch button and try to dodge the swings, while shooting. When they're swinging they're at their most vulnerable and you can land some shots to deal damage.
Aiming accurately is the most important thing. Which gun you pick is just a matter of preference, any will do the job once you get the hang of it. It might take a while and you'll often fail, but practice makes perfect!
Also, if you're playing on a server that gives you a high ping all this will be extra difficult! You should try to pick a server that gives you the lowest possible ping to not gimp yourself from the start. You probably knew this, though.
EDIT: This video by ol' Ben might help too.