Amy Lo's The Book of Mahjong is an elegant book that describes the major Chinese styles of mahjong outside the new official Chinese competition rules. The book starts with a thorough description of Cantonese mahjong, also known as Hong Kong Old Style or old rules. This is a simple style of mahjong with relatively uncomplicated scoring, which makes it a good game for beginners.
Lo's description of the rules should make learning the game easy. There are plenty of pictures to visualize the flow of the game and the way everything works. The scoring is described well. This is a good starting point for a mahjong hobby.
After a short bit about strategy and courtesy in mahjong, Lo delves into Shanghai mahjong, also known as New Style. This is a similar game as the Cantonese mahjong, but there are some changes. The main difference is the scoring: the Shanghai rules include a lot more scoring hands, creating a game that's more interesting but much harder to master.
To finish off the book, Lo describes a simple 12-tile variant (each player has an invisible 13th tile, which works as a wild tile and can replace any tile) and the Taiwanese 16-tile variant.
The book is written well, looks pretty and generally has a clear layout. There are some points where I feel something small is missing (explanation of the fan-laak system, for example) and the book is maintaining the thousand-year myth, but overall this is a welcome addition to my mahjong library.