Not all will be interested in a book about channeling. After all, there are many channels and mediums already - some of them charge for their services while others do not. However, these people have varying levels of proficiency. Some are really good while others are merely delusional. There are also those who are not really psychics but scammers who take advantage of people's cluelessness of the spirit world.
Because getting a good channel or medium can be difficult, it's a good idea that you decided to learn the skill of channeling. You will protect yourself from the ignorant and deceitful if you do the work yourself.
Aside from that, a psychic or medium can relay messages from the spirit to you but unless you know how to distinguish true contact from the false, you can be fooled in many ways. Even if the contact is authentic, it's much better if you don't depend on an outsider to receive and act upon the message.
After all, spirit messages are often highly personal and aimed for the transformation of the individual in many levels. You will get more from the message if you experience it yourself and not simply hear a stranger say it to you.
This book will teach you what channeling is, how it works, and how you can do it to!