I am biased and would prefer to watch it from the beginning... largely because I love the show and want to do that myself if I had the time. Nevertheless, you don't need to watch everything in order to know what is going on now. The start of each arc is an acceptable place to try and pick up the show (though you will miss things obviously).
I would recommend that you start from episode 382, you will get to know the whole crew a just after they are finally assembled. Before this point there are several entertaining arcs in which the crew progresses through the East Blue and then Grand Line fighting Big Bads and gathers new members. The current crew becomes whole in episode 381. You get to see them in one arc together (which provides very important information) and then BIG things happen. You will meet the characters who are the big players in the world as Luffy does and will get quick overviews of the now underpowered big bads from he previous arcs. This is a major turning point for the show and I don't think there is another good place to pick it up again until episode 517. If you start there you will have missed the exact badasses you want to see.
Additionally, I would recommend you watch Strong World. It is a canon movie between (i think) episodes 381 and 382.
Do not think, however, that I am saying that the first 381 episodes are not worth watching. They are amazing and provide important backstory to every character.
I prefer subs and don't know where to find dubs anywhere but Hulu. Sorry for not being able to answer that part.