That particular book was "it" back in the day.... mostly because it was about the only book available on making folders.
I had the book, and at the time, being a rank beginner, found it very frustrating..... because it was written in such a manner that it made it sound like you had to own a certain brand and model of tool to accomplish the task/operation, and the entire book seemed that way to me.
I very much agree with the idea of buying some el-cheapo (or maybe even some not so el-Cheapo) folders, taking them apart, and learning from them.
I think what I learned from doing just that, was many ways NOT to do things, but it lets you see and understand concepts and pieces/parts that you otherwise would not a clear picture of....without seeing them/it in person.