Write for yourself. Write the best book you can. Re-read it. Edit it. Then let two or three (no more than five) people read it. They should be people you trust to give you an honest opinion. If you want to ask your mom or your boyfriend/girlfriend to read it, go ahead. We all like to hear at least one “I love it!” But listen to the general consensus of opinions. If you are hearing consistent comments like: “I was confused by…” or “That one part dragged a little where…” or “I had a hard time with…”, then you might want to check your work and figure out why people are saying these things. If you find you agree with their comments or think sections could be improved, improve them. If you don’t agree, don’t change it. It’s your book.
When you are considering asking people to critique your work, take into consideration who they are and where they are coming from. IT CAN MAKE A DIFFERENCE. And remember, not everyone is going to like your book. I have friends who hated Gone With The Wind and The Lord of The Rings, with comments such as: “Boring” and “Ridiculous.” They are still my friends (sort of). If you expect someone who loves Pynchon and Roth to like your “Bridget Jones Diary-esque” novel, you’re deluded, or someone is a die-hard military history buff to like your Hollywood glitz novel, then you need to rethink your critic list.
A terrific published author, and someone close to me, wrote a very good YA fantasy novel—better than most of the work out there. However, he decided to let several people read it—mostly strangers. The feedback was less than scintillating. Most of these “strangers,” you see, were random authors, (most of them unpublished, I believe), who all had their own ideas of how they would write the book. This author freaked out to the point where he is now, a year later, finishing up the complete rewrite. Knowing him, it will probably be excellent, but that much better than the original? We’ll see.
My point is (although it should be clear by now), that criticisms are important… to a point. When they undermine your work and your own good judgment, you’ve gone too far.