Why this is a mistake: It is possible to get so overwhelmed with feedback on your writing that you stall out. Everyone has an opinion. The question is whether that opinion is of any value. You may desire others’ opinions because you don’t trust or value your own. But remember that while others can often point out problem areas, they rarely can give you good solutions.
Another problem for book writers is that few readers will want—or even be able—to offer feedback on the entire book. If someone isn’t there from the beginning, it’s hard for him to give accurate feedback. Go to the bookstore, pick up a book, read chapter fourteen, and try to critique it without reading the previous thirteen chapters. Kind of hard, isn’t it?
The solution: Find at most three (optimally one or two) readers whose opinions you value and trust. Find readers who will stick with you through the entire manuscript, not readers who will chew up a random chapter and spit it back to you.
And when you do get feedback on your project, evaluate it carefully. Some early critique readers are pretty brutal, others sugarcoat their opinions, and some just aren’t honest. Keep an open mind. As the writer, you have a role to play: You have to be willing to listen to the feedback without reacting negatively. And this is very difficult to do.