If you're like me, it takes actual playing + research to deepen my understanding of the game. While I've been playing Mahjong since I was a child, the big couple of decades break means I'd forgotten simple game-flow elements, as well as not really having an understanding of scoring. Finding a Mahjong group and playing weekly has been so helpful, but I've also been reading and watching how-to videos in between.
Keeping in mind my friends who want to start playing, here are some of the most useful videos I've found so far:
The Tiles of Mahjong (Video by OzMahjong)
Australian presenter.
Very well produced video.
Really easy to listen to and understand basics of the tiles.
Hong Kong Style Mahjong - Training - Episode 1 - The Tiles
Passionate about Hong Kong Mahjong.
This video goes through the tiles.
Note: Does not use flowers or seasons in their play.
How to Mahjong (Basic Hong Kong Style) (Video by Mahjong Sparrow)
Mahjong Sparrow, possibly a New York-based player from Green Tile Social Club.
Really easy to listen to and understand basics of the tiles and how to set up for a Hong Kong style game.
The video description has a number of video links to sets, tables, and mats.
Game Play (Video by OzMahjong)
An easy to watch and listen to video on general game play mechanics.
Very well produced video.
Basics in under 15 minutes (Video by Tainted Mantis)
Easy to listen to and well created video for Beginners for Hong Kong Mahjong.
Recommends: Let's Mahong in 70's Hong Kong Style mobile game to help learn.
Mahjong 101: A beginner's crash course (Hong Kong style) (Video by Wong Side of History)
An easy to watch video, with Mahjong lovingly related to the creator's family history.
Well produced and easy to understand.
Divided into 3 parts, including a history of the game.
Hong Kong Style Mahjong - Training - Episode 2 - Basic rules
Passionate about Hong Kong Mahjong.
This video goes through some more of the mechanics of the game, and game play.
Note: Does not use flowers or seasons in their play.
How to Mahjong with points (Video by Mahjong Sparrow)
Mahjong Sparrow, possibly a New York-based player from Green Tile Social Club.
Starting to explain more complex hands (and better points scoring) hands that can be made.
Length: 16 minutes
After coming back to weekly Mahjong games, at Brisbane Mahjong, watching this video has helped me understand the scoring better.
Beginner's Practice Guide to build up your confidence (Video by Tainted Mantis)
Runs through setting up a virtual game in Let's Mahjong in 70's Hong Kong Style mobile game to help learn.
Hong Kong Mahjong - What to look for when buying a Hong Kong Mahjong Set
From Cantonese Corner, an American who married into Hong Kong Family and lived there for 30 years.
She has a YouTube channel sharing Cantonese language and about Mahjong with her Mother-in-Law.