Looks nice! As I said in the other thread, I cannot properly evaluate the latest Delta Green edition and even my memory of previous editions is a bit fuzzy but it definitely looks functional to me!
Probably (definitely) OT, but since this is a niche topic anyway I hope you don't mind if I take the opportunity to post a couple examples of how I do things. I usually end up organizing my campaigns and player's material in different ways, on a case per case basis. For example, here's some shots of the players journal in my current CoC campaign (on hiatus due to controlavirus):
There are additional pages with npcs portraits, documents they gather, mythos fragments and pictures of various artifacts. It's a good way to keep continuity and give players a tangible sense of progression. Also, I like handouts irl and I miss them when playing online.
As for organizing GM material and structuring campaigns/scenarios, it again depends on the system and the nature of the story itself. My Pathfinder campaigns are much more sandbox-y, although there is a linear sequence of timed events scheduled. I tend to flesh out geography, history and local powers (entities or groups) beforehand, and then leave the players free to roam, interact with locations/people and interject within the events, "scripted" and emerging both.
I find it extremely fun since it allows a non-linear and open ended story to be wrought. I usually have a pretty good idea of the various possible finale a chronicle could reach, but I'm not sure myself about which one the players will go for. And, btw, the two campaigns I'm talking about here are both of the Horror (Terror) kind and heavy on investigation/mistery, this just to give you an idea about why I don't consider linearity a specific trait of Horror/Mistery pnp.
As for CoC, well the game itself
calls for some linearity, for various reasons. First of all, the disparity in strength between players and Cosmic Horrors, you should be
reacting at best. As I said previously, mechanically CoC gives you plenty of tools to confront the evils
you're supposed to confront directly but the general mood should be that the Charaters are barely scraping by. As such, situations in which they are the ones planning direct action beforehand or simply the "freeroaming" approach of other systems, should be very rare. You can definitely play an open campaign (one of my unfinished pet project is a short campaign during the slave rebellion in Haiti, I'd give the players a full topography of the island and play mythos guerrilla, sounds fun in my head) but, once again, there are better systems.
Imho the best approach is to have a linear sequence of open scenarios, the players must agree to go with the flow a bit though. Refusing a questgiver in pathfinder means you go for the next quest, in the next city. While in CoC having the characters being pulled in by the mythos hook itself (the titular
Call of Cthulhu, if you want) should be enough to motivate them into the adventure. Once the quest has been accepted, here's an example of how I structure it:
(beware, unreadable Italian gibberish inside, this is just to give a vague idea of a nonlinear structure)
Each blue square is a different narrative or combat scene, could be both depending on players' actions. The various arrows are hints or clues, which the player can find and which provide direct links to a different location/scene. Obviously, some of those are granted, others require the players to perform specific actions or reach objectives. the important hing here for a proper investigation is
redundancy, you don't want them to stop in their tracks so give them a number of different ways to get to a specific scene. Also, plan around the
total loss of some of those. Sometimes you like the idea of a scene
so much that you try and steer your players into it. Don't do that, unless it's fundamental for the adventure itself, "kill your darlings" is a great advice for would be GM.
So, tl:dr give them space to maneuver inside the adventure itself, if they agree to the base tenet that a CoC campaign is
structured more linearly, they should still have more than enough occasion to creatively affect the gameplay of the session itself.
