You can follow every rule and still write a crappy book. You can commit the most horrendous of writing sins and your book becomes a best seller. It's kinda frustrating if you think about it. It's also a fascinating subject. I talked about this in the post Is Bieng a Good Writer Important?
Here's a post about the topic from Venture Galleries.
"I’ve read books that may have sold only a few dozen books.It's a matter of personal preference. I can't deal with books that tell instead of show, but I'm more forgiving of grammatical errors as long as the book's not overrun with them. You write what you want to read, though I do make sure my stories are free of grammatical errors. Most people aren't as forgiving as I am.
And I loved them.
I’ve read books that have sold thousands, even millions.
And I hated every word.
Don’t like the authors.
Don’t like the books.
Won’t read any more of them.
I have no idea what good writing is.
But I know what makes good books"
(From Would you rather be a good storyteller or a good writer?)
This is an interesting time in writing and publishing. People are taking what we thought was truth and turning it on its head. It gives us more freedom to write what we want, how we want.
This has been hard to accept, though. I've been studying writing and publishing for years. Things are supposed to be done a certain way. My publisher, because it's a small press, has the wiggle room to do things differently. She does. We've had many heated discussions because she wanted to try something that went against everything I knew about the industry. The world would end if the book wasn't handled the proper way or worse, my book wouldn't sell.
There is no proper way to write, publish and promote a book. I'm trying to be more flexible.
How do we write a story someone other than ourselves, and maybe our family, will love?
That's like the question "what makes a bestseller?"
People have opinions. No one knows for sure. More than a little annoying and kinda freeing.
Read often, especially books in your genre. Study them. Find what you like and what pisses you off and just write.