This is just a list of useful info I have found while playing, that I thought would be nice to know from the beginning. If you would rather figure this stuff out while playing, which is more fun for some people, come back after getting some playtime in to learn what you missed.
Tips for Newbies
The compass works from the inventory, and is visible even at night. The steering wheel is usable while doing this.
The fishing pole is usable during any task, meaning you can cast, then trim the sails or set your course, if you catch something, the pole will turn in your hands.
I took me an embarrassingly long time to figure out that you need to scroll to zoom with the Spyglass.
The North Star
If the navigation guide confused you, just remember that the north star is the second star in a short chain of four, with the fourth being furthest from the others.
When your ship begins to list, especially during storms, you can move cargo to either side of the ship to change the center of mass. Most of the time this isn’t necessary, but if full sail is making you take on water, this allows you to stay full sail in rough weather. Depending on how much cargo you have, its very possible to over do it. I’ve found a single crate of copper does the job perfectly.
Remember not to overload the boat, its very possible to make the boat sit low in the water, making it susceptible to storms.
The Aestrin Ship
The Aestrin ship has has a few advantages and disadvantages. It’s biggest problem being the inability to use both sails in the close position, resulting in slow speeds going upwind. The main sail only produces thrust a little more than halfway between the close and beam reach positions, because the sail can only rotate 45 degrees to port and starboard.
In the image you can see the weather vane has metal prongs indicating the max rotation of the main sail. Combined with the metal wind indicator this makes it much easier to tell if the main sail would catch any wind. This is useful because the main sail takes forever to rotate.
As far as I can tell, only the Aestrin ship has this kind of sail, so this only works on this ship. The forward sail has two sheet winches. If you tighten the winch opposite the sail all the way, the sail will produce reverse thrust instead of forward thrust. The main sail also does this if used backwards, though it doesn’t produce as much thrust. This works only in the close and beam reach positions.
If you tighten the sheet winch opposite the forward sail to the close angle, then tack and do the same with the other, you can tack back and forth without further adjustment.