This is pretty bad. The book with the subtitle, "stuff all the pros know and use" has literally no tips from any of the pros. It starts off with super basic things like how many strings are on a mandolin. Not what I expected from a book of tips from the pros.
After that's done, you get taught to use terrible practice habits like always playing a piece from beginning to end. This is pretty much the definition of inefficient practice, and in my lessons I spend a lot of time teaching my students not to do this.
Then he goes on to say you should practice scales while watching tv because "the mind just gets in the way". Seriously, I don't know how this got published. There are so many things in play when you play scales - tone, technique, tension, rhythm, etc., and you won't improve any of them if you're not engaged with what you're playing. Straight up, if you follow these tips you will sabotage your own progress as a mandolinist.
The ending is just a list of famous mandolin players. Interesting enough, but also nothing close to tips from the pros.
If you want to learn mandolin, get Don Julin's "Mandolin for Dummies". It's really good. Or go to mandolincafe.com. Tons of great tips there. But don't read this.