Help required for my first map making project!

[Hai-Etlik]

So I should only use like, Times New Roman, or similar fonts, without texture and without «Outer Glow»?

You don't have to be too austere, but you should think about legibility first. A typeface can have character without being ornate and hard to read. Text halos are a viable technique but you should be careful as they have a very definite "done with a computer" look about them, and you should try to keep them as subtle as possible. It's also a good idea to be austere about colour use in labels. Plain black is usually best. Size, capitalization, slant, italics, and underlining are more commonly used for distinguishing labels.

I can't recommend Positioning Names on Maps enough in terms of advice on labelling.

I think I understand what you are trying to say. I made a very long story for the region first, and tried to put everything that is in the story into an image. This is the result. The whole campaign setting can be found here (in french).

To make a very quick english summary, this region has been slowly flooded twice. It is a very large magical swamp. The Maelstrom at the center is the desperate solution of an alliance of powerful mages to "suck up" the water of the land by constantly magically draining the water in the center (which is then directed back into the Gulf of Dewborn, named after the archdruid they made a pact with to create that delicate balance).

However you are quite right, I don't really know how rivers should behave, I will try to rearrange them by looking at some other maps found here perhaps... My goal is to make the Maelstrom (in the middle of the map) the centerpiece of which everything "water" (rivers mostly) begins or ends. Also, I need a lot of "chaotic rivers" since there is a confederacy of river pirates (who also helped in the creation of the maelstrom, in their own way).

OK so think about how that magic works. I imagine its sort of like changing the gravity so the centre of the map is the bottom of a bowl (even if it's really the top of a mountain), or with that outlet, it might be sort of a half funnel shape. All the water then flows "down" through the system the same way it would otherwise, except that 'downhill' is different. This might be a general change to gravity (not that a fantasy setting would necessarily call it that), but if it affects just water ("down" for water is different from "down" for everything else) you would get some strange effects like the weight of a boat on it is pulling it "upstream" or a pendulum full of water pulling to the side (this might be used as a navigational tool, much like a compass) The "only water" version also raises the question of what water counts (most of the mass of a person is water)

It is really massive magic so it can explain all kinds of oddities. It is worth thinking about those oddities though.

I think I understand what you're trying to say. However I have so many things to put inside that map. I suppose I could (or should) create more "little maps" instead of a giant one, to represent the first chapter of my campaign? This way, I would be able to put "less constant visual density".

And when you say I should moderate my use of textures and patterns, are you talking about the water and the land? Should I just put them "clear blue" and "clear tan" without any textures?

If the map is meant to look like something created IN the setting then elves and dwarves don't generally have Adobe Photoshop. Texture is going to be an unwanted byproduct of the medium (Paper, parchment, cloth, ink, paint, etc) You need to have an idea of the media, and select textures that match. You'll probably have one general texture from the substrate, which will probably be as minimally textured and as white as the in character cartographer can acquire. You've got wildly different textures all over the place and in many places it's quite harsh like the ocean. Using up a lot of contrast between light and dark inside a texture leaves you a lot less for things like making labels on top of that texture clearly legible. Having your background colours solidly in the middle in terms of brightness also leaves you a lot less room to build contrast. Natural media like inks and paints can give some texture as well, but again, it's going to be something the cartographer would be trying to control.

You've also got forest just sort of sprinkled all over. Forests grow where there's enough water for trees and it isn't too cold. If you have that, you should pretty much have forest of some sort or another unless the forest has been removed and prevented from regrowing (such as human activity) That means that if there aren't humans (or whatever) near bay, and it isn't too cold or too dry, you should probably have forest. Where there are people who have figured out agriculture or herding, they generally clear all nearby forest if given the chance. It isn't a simple matter of either trees or people, but your forests would be more believable if they looked like they had some relation to the climate (trees give way to grassland near the desert) and population (dense forests where there are no cities, gaps near cities, and just a few minor woods in areas with significant populations). If you need a gap, you can put a gap somewhere, and if you need a forest, you can put one, but overall, its good to think about the overall distribution.

I'm not personally familiar with Pathfinder but it's my understanding it's pretty much the same kind of dungeon crawling, orc slaying, gonzo adventure game as D&D. As such you can wave your hands and toss in whatever craziness you want and it will "make sense" in the context of the game. Looping rivers and evenly distributed splotches of forest could work just fine.

PS:

I thought maybe an explanation for your complex, looping array of rivers might be that they are magically maintained canals. If the magic is manipulating how water flows that could massively reduce the costs of maintaining navigational canals (locks, dredging, maintaining water levels, etc) Piracy still seems impractical but if some canals were abandoned, but still maintained by the magic, they might explain how the pirates could hide.