You wouldn’t think that was something people needed a guidebook for, given how many truly awful novels get written each year, but according to The Independent the purpose of Sandra Newman and Howard Mittelmark’s book is to help people avoid basic mistakes. The book is subtitled “200 mistakes to avoid at all costs if you ever want to get published”.
One piece of advice that they may have missed is not to get involved in train wreck flame wars like this, which turned up in one of my Google Alerts.