This book could be a very lot better.
It goes on in detail about history, tips, general knowledge and tells to carry a spare bike around with you for spares, but is brief on the maintenance instructions.
There are many photos but all are minute, dark and impossible to see.
It is written specifically for mountain bikes but does not cover some popular systems.
The book progresses to advanced rebuilding of the bike, which I think has gone too far, and I would have preferred more detail on the standard and basic maintenance.
Really this book should have and could have been a very lot better. There has got to be better books out there for the general mountain biker.