Guides
A list of guides taken from the pastebins in the OP, transfered to a more "readable" format

 

General
Strategy
Mahjong Soul

General

Mahjong Live Pastebin

A thorough guide to everything mahjong. Made back in the /jp/ days, it hasn't seen much update in a while but is still perhaps one of the best infodumps around.

I'll try to update this with newer information every now and then.

Mahjong Equipment Buying Guide

Everything you need to know about owning a mahjong set irl.

No Fu Mahjong Teaching Method

From the writer of Hatkagi comes a mahjong teaching method that alledgedly "works great even on kids at the park". A slow crawl approach to teaching the game.

Download Abema VODs

Short instructions to downloading Abema VODs. Learn from the pros.

So you want to play sanma

A guide for people trying to get into sanma (three-player mahjong).

Anon’s Dumbfuck Guide to Chink Vocab in Taiwanese Dominoes 101

A list of Japanese Mahjong terminologies, so you can finally understand the strange moonspeak everyone keeps throwing around.

Glossary of Japanese Mahjong Terms

A glossary of almost every useful Japanese Mahjong term, including the terms listed above, every Yaku in the game, all in an easy filter search.

Hime Mahjong Guide

A guide on Hime Mahjong's interface. Even YOU can be a himebro today.

 

Strategy

How to play Video Game Mahjong

A quick and (relatively) easy guide that teaches you enough mahjong to surf through Mahjong Soul's bronze room. Not to be taken as a consistent mahjong strategy, this is meant more for beginners wanting to get a feel for the game.

Daina Chiba's Riichi Book 1

Do you want to stop being bad at mahjong? Read this. RB1 is essential mahjong reading. Teaches tile efficiency, defense strategies, yaku chasing and everything else to bring you to the level of an intermediate player.

You can also read it online.

Riichi Mahjong Strategy

A book by Fukuchi Makoto and constantly translated by a kind anon. The book is heavily focused on tile efficiency, with a highly digital (analytical) way of thinking. All of the later material about push-fold judgment and discard reading is based on good tile efficiency.

You can also read it online.

Just another Japanese Mahjong blog

Exactly what the label on the tin says. It covers Defence Theory, Riichi Theory and Tile Efficiency, basically a Riichi Book 1. Try this if you find rb1 hard to grasp.

Other Mahjong Blog Sites

Riichi Reporter
Mahjong Guide
The Hopeless Girl on the Path of Houou

These sites have tons of articles and information about mahjong, from news about the growing English Riichi scene to articles about fundamentals and strategy. RIP in peace Osamuko.

Secrets of Iishanten that increases your hand's win rate (Video)

A Japanese youtube video (thankfully with English subtitles) teaching the importance of iishanten (one tile away from ready) and many other things related to it.

Daina Chiba: Lecture I (Bielawa/July 2017)

Daina Chiba's lecture, including things that should be added in Riichi Book 2.

Intermediate Riichi Strategies

A powerpoint presentation pdf by Feng for the intermediate player. It assumes you're already familiar with RB1 and the block method.

50 Shades of Mahjong: WWYDs for Pre-intermediate Players

by krabman (who?), and also assumes you've read rb1. Some wwyds with the logic explained behind the discards.

Tenhou no shikake no shinzui o miyo

Src. An insight on Asapin's (one of the best players on tenhou) calling judgement. It's a complete asapin wankfest but it's a good asapin wankfest.

Wait Winrates
Push/Fold Chart

Some spreadsheet statistics about the winrates of various waits (taken from 1.2 million replays in tenhou's houou table), and a push/fold chart to know what kind of hards are good to push or to fold.

Note: Check the last tab of the Push/Fold chart first to know how to use it.

 

Mahjong Soul

Introduction to Mahjong Soul

An introduction to the ins and outs Mahjong Soul. Go and familiarize yourself with how things works before selling your soul. Also a good guide to have if you want to go through this gatcha hell without spending even a single cent.

Majsoul Plus Guide

A guide for setting up Majsoul plus, a desktop client for Mahjong Soul. Also contains an updated list of mods and extensions shared by based anons in the thread.

Majsoul Plus Modding Guide

A short guide on how to make mods of majsoul plus. Go on and stick your animu waifu in.