Googling and glancing at it this seems decent:
https://en.wikibooks.org/wiki/LaTeX
(I mostly learned LaTeX from Lamport's 1994 LaTex book in the mid 2000s, but wouldn't recommend it today.)
I recommend buying Lamport and reading it. Then write a paper using it. If you need stuff not in Lamport, then the LaTeX Companion is the go-to source.
Not what you wanted, but for reference these books are infinitely better than all the videos in the world plus stackoverflow.
The LaTeX Companion was invaluable to me when I first tried learning LaTeX many years ago. You don't have to read it cover to cover, just read the parts you need as you go. I've almost worn my copy out from so much use. All the online documentation and tutorials are fine, but for me this book was the best way to get started.
A absolutely recommend a text-only format and to store it along with the source code in version control.
I've used reStructuredText for smaller documentations and LaTeX for larger ones. (I also used the LEO text editor to document a large library in HTML/chm, it is interesting but this leans more to the experimental side).
reStructuredText has some specific support which makes it more powerful than Markdown, for example it has extensive support for formatted code listings, and can add tables of content. It has many output options. You can convert it to wikitext, using the pandoc vonversion utility. Also, github can render it. There is a python pip package called restview which renders your document in the browser, including links, while you type it - this works very smoothly.
With LaTeX, code listings (I guess you don't need them here) be done using the "minted" Package. What makes LaTeX extremely good specifically for the purpose of documentation is, apart from a very consistent formatting, its support for a keyword index. And this is something you really need to make information discoverable in a large documentation. It is actually fun to build it. You can compile documents to different paper sizes, one in B5 which fits well as a PDF on a medium screen, and one for printing on A4 paper, for example. With the right font settings, it looks really really good and top notch readable.
Book recommendation (and a good example on how to do it well) : Leslie Lamport, LaTeX, A Document Preparation System.
Edit: Also, I have good experiences with inkscape for graphics. Readers love graphics.
Edit: Racket's scribble has been mentioned. I think it is good.
knuth's texbook has pg 17 in preview if you want to see an example
https://www.amazon.com/TeXbook-Donald-Knuth/dp/0201134489
I don't know if I would call that geometric; to me additive is a better word
You should probably start with Leslie Lamport's classic. It's clear, thorough, and concise. It also has a reference section in the back where you can look things up quickly if you forget some particular syntax. Plus the drawings in the book are really cute! After reading this book you can move on to some of the more modern tutorials people have linked to.
You should really calibrate to the stock and create an output profile for each stock you use.
This page should be a good resource to delve into the print world: http://colorremedies.com/realworldcolor/downloads.html Granger rainbow and rgb explorer are in this page somewhere to download for free.
Also, read this book: Real World Color Management (2nd Edition) https://www.amazon.com/dp/0321267222/ref=cm_sw_r_cp_apa_BweXzbSD9Y08P
Most of the time coated swop will suffice. ��
Perhaps have a look at this book: Intellectual Property and Open Source: A Practical Guide to Protecting Code by Van Lindberg.
Find a good book. I have one (I think it's this one: https://www.amazon.com/dp/0201362996/ref=cm_sw_r_taa_ZBGxxbFYM23S2) and the fact it shows you a ton of packages and how to use them fantastic. I haven't come across a tutorial that has remotely as much info as that book.
It all depends on what projects you'd like to do. So if you want to make websites, the place to start is HTML, CSS and Java Sccript.
If you wanna make iOS apps, you'll need to know Swift, ObjectiveC and C++. And if you wanna build Android apps you also need to know C. Thourghouty understand Java. For all three of those types of projects it'll help to know sql databases and database structures.
The easiest coding environment is X-code. This is Apples coding environment to build iOS Apps. Also, people like to work in Microsoft Visual Studio. If you don't choose any of those routes there's always good old fashion coding with text! Codecademy is good, however, it will be limited with what it actually teaches you how to do.
For resources: on design read TapWorthy for Apps.http://www.amazon.com/Tapworthy-Designing-Great-iPhone-Apps/dp/1449381650
This might be a little outdated for iOS 9, however, if you wanna learn the basics of wire framing, it's a great place to start.
The coding book series by John Duckett is another great tool. http://www.amazon.com/HTML-CSS-Design-Build-Websites/dp/1118008189
These are great books to teach visually minded people, like myself, to code. Coding and learning to code is certainly a process. The best coders that my team uses are the ones that really commit themselves to the craft of it. It helps to have an engineering mind, but truthfully, if you can learn to speak Spanish, you can learn to write code!
I think you added already the ones I recommend highly but additionally:
Grid systems - Josef M B
Anything by Steven Heller, he spits out a book every second.
archive.org has a ton of free stuff that's really good.
U&LC Herb Lubalin and lastly Spiekermann
The "Graphic Design Referenced" book published by rockport in the title post is a great resource for beginners n intermediate, infact it's an amazing book, it covers everything in small detail, from typography to every known designer that lived, posters, etc.
I read your rant and flashed back to the Philip And Alex Guide to Web Publishing -- which I read 15 years ago!
So don't hold your breath waiting for websites to start being designed rationally.