I'll try on this but my memory is a bit fuzzy concerning where to go if you're British.
Gang Signals is the first part of the chain. You'd pick it up at Bartica then go abouts to the other three starter ports of Whitby, Sisal and Tampa I believe.
After you're done with that, you'd want to head up to Belize, Ambergris and Bluefields for the 2nd chapter.
Iguana and Harbour Island run the third parts with Harbour Island being the daily "Baptism by fire" mission.
The fourth part in the chain should be the treasure map missions. They start off in your Capitol and send you to Oranjestad then across the world map.
Pointe-A-Pitre magistrate's office will have another bit which sends you across to Santo Domingo, Nassau, Cayo de Marquis, Sisal and someplace else I can't remember to stop the Dread Saints from unifying the pirate gangs. Also get a set of gloves out of it.
Its not much but I hope this helps you somewhat on where to go and what to do.