I don't think anyone would be foolish enough to think they could go to a hospital and perform surgery just because they read a book about surgery.  I don't think anyone would believe they could build a bridge just because they read a book or two on engineering.      
    There are some simple things you can learn to do just by reading a book, but the more complex things require practice and working with a teacher and/or being apprenticed to an expert in the field.
    Unfortunately, many people thing that spiritual development is one of those simple things that can be done just bey reading a book or perhaps attending some weekend seminar.  I have to disagree with that for several reasons:
Those books usually contain only the most basic spiritual teachings, no reputable spiritual teacher would put the more advanced teachings in a book
The books can't account for the fact that we are starting from different points, have different backgrounds, and respond to different teaching methods
The book has no way of recognizing that you have taking a wrong turn, are heading toward the negative, dark side of spirit, and need to be pulled back and returned to the correct path.

While learning from book is great, I do it all the time, If you want to get serious about developing your spiritual faculties you need to work with a spiritual school or instructor that can provide that training.